5G Management, Orchestration & Charging

Management, Orchestration and Charging for 5G networks

Key topics for modern 5G networks include Management, Orchestration and Charging. In December 2017, the 3GPP passed two major milestones for 5G by approving the first set of 5G NR specs and by putting in place the 5G Phase 1 System Architecture. These achievements have brought about the need for new management standards, as 5G adds to the ever-growing size and complexity of telecom systems.

3GPP management standards from working group SA5 are approaching another major milestone for 5G. With our studies on the 5G management architecture, network slicing and charging completed last year, we are now well under way with the normative work for the first phase in 3GPP Release 15, which includes building up a new service-oriented management architecture and all the necessary functionalities for management and charging for 5G networks.

SA5’s current work also includes several other work/study items such as management of QoE measurement collection and new technologies for RESTful management protocols. However, this article will focus on the new 5G Rel-15 architecture and the main functionalities, including charging.

5G networks and network slicing

Management and orchestration of 5G networks and network slicing is a feature that includes the following work items: management concept and architecture, provisioning, network resource model, fault supervision, assurance and performance management, trace management and virtualization management aspects. With the output of these work items, SA5 provides specified management interfaces in support of 5G networks and network slicing. An operator can configure and manage the mobile network to support various types of services enabled by 5G, for example eMBB (enhanced Mobile Broadband) and URLLC (Ultra-Reliable and Low Latency Communications), depending on the different customers’ needs. The management concept, architecture and provisioning are being defined in TS 28.530, 28.531, 28.532 and 28.533. 

Network slicing is seen as one of the key features for 5G, allowing vertical industries to take advantage of 5G networks and services. 3GPP SA5 adopts the network slice concept as defined in SA2 and addresses the management aspects. Network slicing is about transforming a PLMN from a single network to a network where logical partitions are created, with appropriate network isolation, resources, optimized topology and specific configuration to serve various service requirements.

As an example, a variety of communication service instances provided by multiple Network Slice Instances (NSIs) are illustrated in the figure below. The different parts of an NSI are grouped as Network Slice Subnets (e.g. RAN, 5GC and Transport) allowing the lifecycle of a Network Slice Subnet Instance (NSSI) to be managed independently from the lifecycle of an NSI.

5G Management, Orchestration & Charging

Provisioning of network slice instances

The management aspects of a network slice instance can be described by the four phases:

1) Preparation: in the preparation phase the network slice instance does not exist. The preparation phase includes network slice template design, network slice capacity planning, on-boarding and evaluation of the network slice requirements, preparing the network environment and other necessary preparations required to be done before the creation of a network slice instance.

2) Commissioning: provisioning in the commissioning phase includes creation of the network slice instance. During network slice instance creation all needed resources are allocated and configured to satisfy the network slice requirements. The creation of a network slice instance can include creation and/or modification of the network slice instance constituents.

3) Operation: includes the activation, supervision, performance reporting (e.g. for KPI monitoring), resource capacity planning, modification, and de-activation of a network slice instance. Provisioning in the operation phase involves activation, modification and de-activation of a network slice instance.

4) Decommissioning: network slice instance provisioning in the decommissioning phase includes decommissioning of non-shared constituents if required and removing the network slice instance specific configuration from the shared constituents. After the decommissioning phase, the network slice instance is terminated and does not exist anymore.

Similarly, provisioning for a network slice subnet instance (NSSI) includes the following operations:

  • Create an NSSI;
  • Activate an NSSI;
  • De-active an NSSI;
  • Modify an NSSI;
  • Terminate an NSSI.

Roles related to 5G networks and network slicing

The roles related to 5G networks and network slicing management include: Communication Service Customer, Communication Service Provider (CSP), Network Operator (NOP), Network Equipment Provider (NEP), Virtualization Infrastructure Service Provider (VISP), Data Centre Service Provider (DCSP), NFVI (Network Functions Virtualization Infrastructure) Supplier and Hardware Supplier.

Depending on actual scenarios:

  • Each role can be played by one or more organizations simultaneously;
  • An organization can play one or several roles simultaneously (for example, a company can play CSP and NOP roles simultaneously).
Management models for network slicing
5G Orchestration

Management models for network slicing

Different management models can be used in the context of network slicing.

1) Network Slice as a Service (NSaaS): NSaaS can be offered by a CSP to its CSC in the form of a communication service. This service allows CSC to use and optionally manage the network slice instance. In turn, this CSC can play the role of CSP and offer their own services (e.g. communication services) on top of the network slice instance. The MNSI (Managed Network Slice Instance) in the figure represents a network slice instance and CS represents a communication service.

2) Network Slices as NOP internals: network slices are not part of the CSP service offering and hence are not visible to CSCs. However, the NOP, to provide support to communication services, may decide to deploy network slices, e.g. for internal network optimization purposes.

5G Network Slice As A Service

Management architecture

SA5 recognizes the need for automation of management by introducing new management functions such as a communication service management function (CSMF), network slice management function (NSMF) and a network slice subnet management function (NSSMF) to provide an appropriate abstraction level for automation.

The 3GPP SA5 management architecture will adopt a service-oriented management architecture which is described as interaction between management service consumer and management service provider. For example, a management service consumer can request operations from management service providers on fault supervision service, performance management service, provisioning service and notification service, etc.

Network Resource Model (NRM) for 5G networks and network slicing

To support management and orchestration of 5G networks, the Network Resource Model (NRM) representing the manageable aspects of 5G networks needs to be defined, according to 5G network specifications from other 3GPP working groups as well as considering requirements from 5G management architecture and operations.

The 5G NRM specifications family includes 4 specifications: TS 28.540 and TS 28.541 for NRM of NR and NG-RAN, TS 28.542 and TS 28.543 for NRM of 5G core network.

According to content categorization, 5G NRM specifications can be divided into 3 parts:

  • Requirements, also known as stage 1,
  • Information Model definitions also known as stage 2, and
  • Solution Set definitions also known as stage 3.

Identified in the specifications of 5G NRM requirements (TS 28.540 and TS 28.542), the NRM of 5G network comprises NRM for the 5G core network (5GC) and NRM for 5G radio access network (i.e. NR and NG-RAN). The 5GC NRM definitions support management of 5GC Network Functions, respective interfaces as well as AMF Set and AMF Region. The NR and NG-RAN NRM definitions cover various 5G radio networks connectivity options (standalone and non-standalone radio node deployment options) and architectural options (NR nodes with or without functional split).

The 5G Information Model definitions specify the semantics and behavior of information object class attributes and relations visible on the 5G management interfaces, in a protocol and technology neutral way (UML as protocol-neutral language is used). The 5G Information Model is defined according to 5GC, NR and NG-RAN specifications. For example, in 3GPP TS 38.401, the NR node (gNB) is defined to support three functional split options (i.e. non-split option, two split option with CU and DU, three split option with CU-CP, CU-UP and DU), so in the NR NRM Information Model, corresponding Information Object Class (IOC) is defined for each network function of gNB specified, and different UML diagrams show the relationship of each gNB split option respectively. Further, in the 5G Information Model definitions, the existing Generic NRM Information Service specification (TS 28.622) is referenced to inherit the attributes of generic information object classes, and the existing EPC NRM Information Service specification (TS 28.708) is referenced for 5GS / EPS interworking relationships description.

Finally, NRM Solution Set definitions map the Information Model definitions to a specific protocol definition used for implementations. According to recommendation from TR 32.866 (Study on RESTful based Solution Set), JSON is expected to be chosen as data modelling language to describe one 5G NRM Solution Set.

Fault Supervision of 5G networks and network slicing

Fault Supervision is one of the fundamental functions for the management of a 5G network and its communication services. For the fault supervision of 5G networks and network slicing, the following 3GPP TSs are being specified:

1) TS 28.545 “Management and orchestration of networks and network slicing; Fault Supervision (FS); Stage 1”, which includes:

  • The use cases and requirements for fault supervision of 5G networks and network slicing.
  • The definitions of fault supervision related management services (e.g. NetworkSliceAlarmAcknowledgement, NetworkSliceAlarmListReading, NetworkSliceAlarmClearance, NetworkSliceAlarmNotification, NetworkSliceAlarmSubscription, etc.)

2) TS 28.546 “Management and orchestration of networks and network slicing; Fault Supervision (FS); Stage 2 and stage 3”, which includes the definition of:

  • Interfaces of the fault supervision related management services; (Stage 2)
  • Notifications; (Stage 2)
  • Alarm related information models (e.g. alarmInformation, alarmList, etc.); (Stage 2)
  • Solution set(s) (e.g. RESTful HTTP-based solution set for Fault Supervison); (Stage 3)
  • New event types and probable causes if necessary. 

Assurance data and Performance Management for 5G networks and network slicing

The 5G network is designed to accommodate continuously fast increasing data traffic demand, and in addition, to support new services such as IoT, cloud-based services, industrial control, autonomous driving, mission critical communications, etc. Such services may have their own performance criteria, such as massive connectivity, extreme broadband, ultra-low latency and ultra-high reliability.

The performance data of the 5G networks and NFs (Network Functions) are fundamental for network monitoring, assessment, analysis, optimization and assurance. For the services with ultra-low latency and ultra-high reliability requirements, any faults or performance issues in the networks can cause service failure which may result in serious personal and property losses. Therefore, it is necessary to be able to collect the performance data in real-time (e.g., by performance data streaming), so that the analytic applications (e.g., network optimization, SON, etc.) could use the performance data to detect any network performance problems, predict the potential issues and take appropriate actions quickly or even in advance.

For network slicing, the communication services are provided on top of the end-to-end network slice instances, so the performance needs to be monitored from end-to-end point of view.

The end to end performance data of 5G networks (including sub-networks), NSIs (Network Slice Instances) and NSSIs (Network Slice Subnet Instances) are vital for operators to know whether they can meet the communication service requirement.

The performance data may be used by various kinds of consumers, such as network operator, SON applications, network optimization applications, network analytics applications, performance assurance applications, etc. To facilitate various consumers to get their required performance data, the following items are being pursued by this WI:

  • A service based PM framework and a list of PM services as described in the table below:  
Management service nameManagement service description
NF measurement job control service
The management service for creating and terminating the measurement job(s) for the NF(s).
NF measurement job information service
The management service for querying the information of the measurement job(s) for the NF(s).
NF performance data file reporting Service
The management service for reporting the NF performance data file.
NF performance data streaming service
The management service for providing streaming of NF performance data.
NSSI measurement job control service
The management service for creating and terminating the measurement job(s) for the NSSI(s).
NSSI measurement job information service
The management service for querying the information of the measurement job(s) for the NSSI(s).
NSSI performance data file reporting Service
The management service for reporting the NSSI performance data file.
NSSI performance data streaming service
The management service for providing streaming of NSSI performance data.
NSI measurement job control service
The management service for creating and terminating the measurement job(s) for the NSI(s).
NSI measurement job information service
The management service for querying the information of the measurement job(s) for the NSI(s).
NSI performance data file reporting Service
The management service for reporting the NSI performance data file.
NSI performance data streaming service
The management service for providing streaming of NSI performance data.
Network measurement job control service
The management service for creating and terminating the measurement job(s) to collect the network performance data that is not specific to network slicing.
Network measurement job information service
The management service for querying the information of the measurement job(s) to collect the network performance data that is not specific to network slicing.
Network performance data file reporting service
The management service for reporting the network performance data file that is not specific to network slicing.
Network performance data streaming service
The management service for providing network performance data streaming that is not specific to network slicing.
  • Performance measurements (including the data that can be used for performance assurance) for 3GPP NFs;
  • End to end KPIs, performance measurements (including the data that can be used for performance assurance) for NSIs, NSSIs and networks (where the performance data is not specific to network slicing).

Management and virtualization aspects of 5G networks

For 5G networks, it is expected that most of the network functions will run as software components on operators’ telco-cloud systems rather than using dedicated hardware components. Besides the virtualization for Core Network (including 5GC, EPC and IMS), the NG-RAN architecture is being defined with functional split between central unit and distributed unit, where the central unit can also be virtualized.

SA5 has conducted a study on management aspects of the NG-RAN that includes virtualized network functions, and has concluded in TR 32.864 that the existing specifications (related to management of mobile networks that include virtualized network functions) need some enhancements for 5G. The enhancements are mainly on the interactions between 3GPP management system and external management systems (e.g., ETSI NFV MANO) for the following aspects:

  • Management requirements and architecture;
  • Life Cycle Management (e.g., PNF management);
  • Configuration Management;
  • Performance Management;
  • Fault Management.

There are gaps identified between 3GPP SA5 requirements and ETSI ISG NFV solutions in terms of the required enhancements, and 3GPP SA5 is in cooperation with ETSI ISG NFV to solve these gaps.

Although the need for enhancements were found in the study for 5G, SA5 has reached the conclusion that they can be the used for 4G as well. So the specifications for management of mobile networks that include virtualized network functions are being made generally applicable to both 4G and 5G networks.

Study on energy efficiency of 5G networks

Following the conclusions of the study on Energy Efficiency (EE) aspects in 3GPP Standards, TSG SA#75 recommended initiating further follow-up studies on a range of energy efficiency control related issues for 5G networks including the following aspects:

  • Definition and calculation of EE KPIs in 3GPP Systems
  • Energy Efficiency control in 3GPP Systems
  • Coordinated energy saving in RAN and other subsystem in 3GPP Systems
  • Power consumption reduction at the site level
  • Energy Efficiency in 3GPP systems with NFV
  • Energy Efficiency in Self-Organizing Networks (SON). 

TR 32.972 (Study on system and functional aspects of energy efficiency in 5G networks) aims to:

  • Identify EE KPI definitions made by ETSI TC EE, ITU-T SG5, ETSI NFV ISG, etc., which are relevant for 5G networks, in addition to definitions made in SA TR 21.866. Such EE KPIs can be defined at various levels, incl. network and equipment levels (potentially, at virtualized network function and virtualized resource level), and per deployment scenario (dense urban, rural, etc.). With 5G, potentially, EE KPIs can be defined at network slice level;
  • Identify metrics to be defined by 3GPP so as to be able to calculate the above EE KPIs for 5G networks. Such metrics might relate to data volumes, coverage area or energy consumption;
  • Assess whether existing OA&M mechanisms enable to control and monitor the identified metrics. In particular, check if the IRP for the control and monitoring of Power, Energy and Environmental (PEE) parameters for Radio Access Networks (RAN) (TS 28.304, 28.305, 28.306) can be applied to 5G networks. If not, identify potential new OA&M mechanisms;
  • Elaborate further on the EE control framework defined in TR 21.866 and identify potential gaps with respect to existing management architectures, incl. SON and NFV based architectures;
  • Examine whether new energy saving functionalities might enable the 3GPP management system to manage energy more efficiently. In particular, the applicability of ETSI ES 203 237 (Green Abstraction Layer; Power management capabilities of the future energy telecommunication fixed network nodes) to the management of 5G networks is to be evaluated;
  • Identify potential enhancements in existing standards which could lead to achieving improved 3GPP system-wide energy efficiency.

This study requires interactions with other 3GPP working groups and SDOs working on related topics, including ITU-T SG5, ETSI TC EE, ETSI NFV ISG.

5G Charging system architecture and service based interface

Commercial deployment of the Rel-15 5G System will not be possible without capabilities for Operators to be able to monetize the various set of features and services which are specified in TS 23.501, TS 23.502 and TS 23.503. This is defined under the charging framework, which includes e.g. real-time control of subscriber’s usage of 5G Network resources for charging purpose, or per-UE data collection (e.g. for CDRs generation) which can also be used for other purposes e.g. analytics.

SA5 has investigated, during a study period in 2017, on how charging architecture should evolve, which key features should be specified as part of charging capabilities, and which alternative amongst charging solutions should be selected, to better support the first commercial 5G system deployment. Based on the study results, the charging architecture evolution and selected Rel-15 key functionalities for 5G system are under ongoing normative phase through development of a complete set of specifications (architecture, functionalities and protocols) A brief overview of the charging coverage for the Rel-15 5G system is provided in this article.

Service Based Interface

One key evolution of the charging architecture is the adoption of a service based interface integrated into the overall 5G system service based architecture, enabling deployments of charging functions in virtualized environment and use of new software techniques. The new charging function (CHF) introduced in the 5G system architecture, as shown in the picture below, allows charging services to be offered to authorized network functions. A converged online and offline charging will also be supported. 

5G Service Based Interface, Orchestration

While offering the service based interface to the 5G system, the overall converged charging system will be able to interface the billing system as for the existing system (e.g. 4G) to allow Operators to preserve their billing environment. These evolutions are incorporated in the TS 32.240 umbrella architecture and principles charging specification. The services, operations and procedures of charging using Service Based Interface will be specified in a new TS 32.290, and TS 32.291 will be the stage 3 for this interface.

5G Data connectivity charging

The “5G Data connectivity charging”, achieved by SMF invocation of charging service(s) exposed by the charging function (CHF), will be specified in a new TS 32.255, encompassing the various configurations and functionalities supported via the SMF, which are highlighted below.

For 3GPP network deployments using network slicing, by indicating to the charging system which network slice instance is serving the UE during the data connectivity, the Operator will be able to apply business case charging differentiation. Further improvements on flexibility in charging systems deployments for 5G network slicing will be explored in future releases.

The new 5G QoS model introduced to support requirements from various applications in data connectivity, is considered to support QoS based charging for subscriber’s usage. 5G QoS-based charging is also defined to address inter-Operator’s settlements (i.e. between VPLMN and HPLMN) in roaming Home-routed scenario.

All charging aspects for data services in Local breakout roaming scenarios will be further considered.

In continuation with existing principles on Access type traffic charging differentiation, the two Access Networks (i.e. NG-RAN and untrusted WLAN access) supported in Rel-15 are covered.

Charging capabilities encompass the various functionalities introduced in the 5G system to support flexible deployment of application functions (e.g. edge computing), such as the three different Session and Service Continuity (SSC) modes and the Uplink Classifiers and Branching Points.

Charging continuity for interworking and handover between 5G and existing EPC is addressed.

In 5G Multi-Operator Core Network sharing architecture (i.e. shared RAN), identification of the PLMN that the 5G-RAN resources were used for to convey the traffic, allows settlements between Operators.

The stage 3 for “5G data connectivity charging” will be available in TS 32.298 for the CDRs’ ASN.1 definition and in TS 32.291 for the data type definition in the protocol used for the service based interface.

Note:

Above content on 5G is from 3GPP and is (C) 3GPP.

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5G Disaggregated Network Topology Split Options

Functional Split Options for gNodeB 5G-NR Base Stations

A major benefit of 5G for Mobile Network Operators (MNOs) is the prospect of migrating from custom network nodes to a far more flexible approach that enables network nodes to be implemented in software running on generic hardware platforms. In the core network, this process is in an advanced state, with virtualisation and orchestration techniques from the IT world now being used to deploy network functions automatically at a large scale. The functional “split” is key to achieving efficiency gains.

The process is significantly more difficult in the RAN and backhaul network, and the prize for MNOs is greater here as these functions typically account for 70-80% of Capex. In Release 15, the 3GPP identified various functional splits in the 5G NR RAN gNodeB (base station) that would facilitate this process, identifying eight possible places where the gNodeB function could be split into separate functional units. The most popular of these “split” options are:

Split 0 – gNodeB Integrated Small Cell

The gNodeB is a traditional integrated 5G NR with the RF, PHY and stack layers integrated into a single unit, with an NG interface to the 5GC Core Network.

Split 2 – 3GPP F1

The 3GPP defines this disaggregated RAN with separate (gNodeB-)CU and (gNodeB-)DU units with a high level split 2 using the 3GPP defined F1 interface. Split 2 is sometimes used in conjunction with a lower level splits 6, 7.2 and 8. This new 3GPP 5G RAN architecture introduces new terminology, interfaces and functional modules.

Split 6 – Small Cell Forum (SCF) nFAPI

The split 6 interface protocol is the Network FAPI (nFAPI), specified by the Small Cell Forum, where the MAC and PHY functions are physically separate.

Split 7.2 – O-RAN Open Fronthaul

A split 7 interface has been specified by the O-RAN Alliance, which has adopted the eCPRI interface as its basis. Whereas CPRI passes antenna samples using a proprietary protocol, eCPRI uses Ethernet.

Split 8

The split 8 interface is mainly being considered where there are legacy systems and existing hardware and cabling/fibre can be reused.

Industry Body Backed Split Option Definitions

3GPP specified the higher layer F1 interface, but additional interfaces at lower layer splits have also been specified by other industry bodies, and offer different relative advantages and disadvantages.

  • The Split 6 interface protocol is the Network FAPI (nFAPI), specified by the Small Cell Forum, where the MAC and PHY functions are physically separate.
  • The Split 7 interface has been specified by the O-RAN Alliance, which has adopted the eCPRI interface as its basis. Whereas CPRI passes digitised RF signals to the antenna using a proprietary serial protocol, eCPRI uses Ethernet. Moreover, in O-RAN fronthaul, it is frequency domain samples that are transported between the upper PHY and lower PHY, which leads to advantages.
  • The Split 8 interface is mainly being considered where there are legacy systems and existing hardware and cabling/fibre can be reused.

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5G NR Frame Structure

Exploring the 5G NR Frame Structure used in 5G New Radio networks and 5G Radio equipment: including gNodeB and 5G CPE devices

Frame Structure

The 5G NR frame structure is defined by the 3GPP and here we present details of the NR Frame Structure that is specified in 3GPP specification (38.211).

Numerology – Subcarrier Spacing

Compared to LTE numerology (subcarrier spacing and symbol length), the most outstanding difference you can notice is that NR support multiple different types of subcarrier spacing (in LTE there is only one type of subcarrier spacing, 15 KHz). The types NR numerology is summarized in 38.211 and I converted the table into illustration to give you intuitive understanding of these numerology.

As you see here, each numerology is labeled as a parameter(u, mu in Greek). The numerology (u = 0) represents 15 kHz which is same as LTE. And as you see in the second column the subcarrier spacing of other u is derived from (u=0) by scaling up in the power of 2.

5G Frame Structure

Numerology and Slot Length

As illustrated below, Slot length gets different depending on numerology. The general tendency is that slot length gets shorter as subcarrier spacing gets wider. Actually this tendency comes from the nature of OFDM. You would see further details on how the slot length is derived in Radio Frame Structure section.

5G Frame Structure Slot

Numerology and Supported Channels

Not every numerology can be used for every physical channel and signals. That is, there is a specific numerologies that are used only for a certain type of physical channels even though majority of the numerologies can be used any type of physical channels. Following table shows which numerologies can be used for which physical channels.

< 38.300-Table 5.1-1: Supported transmission numerologies and additional info.>

OFDM Symbol Duration

Parameter / Numerlogy (u)01234
Subcarrier Spacing (Khz)153060120240
OFDM Symbol Duration (us)66.6733.3316.678.334.17
Cyclic Prefix Duration (us)4.692.341.170.570.29
OFDM Symbol including CP (us)71.3535.6817.848.924.46

Numerology – Sampling Time

Sampling time can be defined differently depending on Numerogy (i.e, Subcarrier Spacing) and in most case two types of Timing Unit Tc and Ts are used.

  • Tc = 0.509 ns
  • Ts = 32.552 ns

See Physical Layer Timing Unit page to see how these numbers are derived and to see some other timing units.

Radio Frame Structure

As described above, in 5G/NR multiple numerologies(waveform configuration like subframe spacing) are supported and the radio frame structure gets a little bit different depending on the type of the numerology. However, regardless of numerology the length of one radio frame and the length of one subfame is same.  The length of a Radio Frame is always 10 ms and the length of a subframe is always 1 ms. 

What changes to accommodate the physical property of the different numerology ? Answer is to put different number of slots within one subfame. There is another varying parameter with numerology. It is the number of symbols within a slot. However, the number of symbols within a slot does not change with the numerology, it only changes with slot configuration type. For slot configuration 0, the number of symbols for a slot is always 14 and for slot configuration 1, the number of symbols for a slot is always 7.

Now look at details of radio frame structure for each numerology and slot configuration:

< Normal CP, Numerology = 0 >

In this configuration, a subframe has only one slot in it, it means a radio frame contains 10 slots in it. The number of OFDM symbols within a slot is 14.

5G radio frame structure

< Normal CP, Numerology = 1 >

In this configuration, a subframe has 2 slots in it, it means a radio frame contains 20 slots in it. The number of OFDM symbols within a slot is 14.

< Normal CP, Numerology = 2 >

In this configuration, a subframe has 4 slots in it, it means a radio frame contains 40 slots in it. The number of OFDM symbols within a slot is 14.

< Normal CP, Numerology = 3 >

In this configuration, a subframe has 8 slots in it, it means a radio frame contains 80 slots in it. The number of OFDM symbols within a slot is 14.

< Normal CP, Numerology = 4 >

In this configuration, a subframe has 16 slots in it, it means a radio frame contains 160 slots in it. The number of OFDM symbols within a slot is 14.

< Extended CP, Numerology = 2 >

In this configuration, a subframe has 8 slots in it, it means a radio frame contains 80 slots in it. The number of OFDM symbols within a slot is 12.

Slot Format

Slot Format indicates how each of symbols within a single slot is used. It defines which symbols are used for uplink and which symbols are used for downlink within a specific slot. In LTE TDD, if a subframe (equivalent to a Slot in NR) is configured for DL or UL, all of the symbols within the subframe should be used as DL or UL. But in NR, the symbols within a slot can be configured in various ways as follows.

  • We don’t need to use every symbols within a slot (this can be a similar concept in LAA subframe where only a part of subframes can be used for data transmission).
  • Single slot can be devided into multiple segments of consecutive symbols that can be used for DL , UL or Flexible.

Theoretically we can think of almost infinite number of possible combinations of DL symbol, UL symbol, Flexible Symbol within a slot, but 3GPP allows only 61 predefined symbol combination within a slot as in following table. These predefined symbol allocation of a slot called Slot Format. (For the details on how these Slot Format is being used in real operation, refer to Slot Format Combination page).

<38.213 v15.7 -Table 11.1.1-1: Slot formats for normal cyclic prefix>

D : Downlink, U : Uplink, F : Flexible

 Symbol Number in a slot
Format012345678910111213
0DDDDDDDDDDDDDD
1UUUUUUUUUUUUUU
2FFFFFFFFFFFFFF
3DDDDDDDDDDDDDF
4DDDDDDDDDDDDFF
5DDDDDDDDDDDFFF
6DDDDDDDDDDFFFF
7DDDDDDDDDFFFFF
8FFFFFFFFFFFFFU
9FFFFFFFFFFFFUU
10FUUUUUUUUUUUUU
11FFUUUUUUUUUUUU
12FFFUUUUUUUUUUU
13FFFFUUUUUUUUUU
14FFFFFUUUUUUUUU
15FFFFFFUUUUUUUU
16DFFFFFFFFFFFFF
17DDFFFFFFFFFFFF
18DDDFFFFFFFFFFF
19DFFFFFFFFFFFFU
20DDFFFFFFFFFFFU
21DDDFFFFFFFFFFU
22DFFFFFFFFFFFUU
23DDFFFFFFFFFFUU
24DDDFFFFFFFFFUU
25DFFFFFFFFFFUUU
26DDFFFFFFFFFUUU
27DDDFFFFFFFFUUU
28DDDDDDDDDDDDFU
29DDDDDDDDDDDFFU
30DDDDDDDDDDFFFU
31DDDDDDDDDDDFUU
32DDDDDDDDDDFFUU
33DDDDDDDDDFFFUU
34DFUUUUUUUUUUUU
35DDFUUUUUUUUUUU
36DDDFUUUUUUUUUU
37DFFUUUUUUUUUUU
38DDFFUUUUUUUUUU
39DDDFFUUUUUUUUU
40DFFFUUUUUUUUUU
41DDFFFUUUUUUUUU
42DDDFFFUUUUUUUU
43DDDDDDDDDFFFFU
44DDDDDDFFFFFFUU
45DDDDDDFFUUUUUU
46DDDDDFUDDDDDFU
47DDFUUUUDDFUUUU
48DFUUUUUDFUUUUU
49DDDDFFUDDDDFFU
50DDFFUUUDDFFUUU
51DFFUUUUDFFUUUU
52DFFFFFUDFFFFFU
53DDFFFFUDDFFFFU
54FFFFFFfDDDDDDD
55DDFFFUUUDDDDDD
62-254Reserved
255UE determines the slot format for the slot based on tdd-UL-DL-ConfigurationCommon, or tdd-ULDL-ConfigurationDedicated and, if any, on detected DCI formats

Why we need so many different types of slot formats ? Key goal is to make NR scheduling flexible especially for TDD operation. By applying a slot format or combining different slot formats in sequence, we can implement various different types of scheduling as in the following example:

TDD DL/UL Common Configuration

See  TDD DL/UL Common Configuration page.

Resource Grid

The resource grid for NR is defined as follows. If you just take a look at the picture, you would think it is almost identical to LTE resource grid. But the physical dimension (i.e, subcarrier spacing, number of OFDM symbols within a radio frame) varies in NR depending on numerology.

5G NR Frame

The maximum and minimum number of Resource blocks for downlink and uplink is defined as below (this is different from LTE)

< 38.211 v1.0.0 Table 4.4.2-1: Minimum and maximum number of resource blocks.>

Following is the table that I converted the downlink portions of Table 4.4.2-1 into frequency Bandwidth just to give you the idea on what is the maximum RF bandwidth that a UE / gNB need to support for single carrier.

umin RBMax RBsub carrier spacing(kHz)Freq BW min(MHz)Freq BW max(MHz)
024275154.3249.5
124275308.6499
2242756017.28198
32427512034.56396
42413824069.12397.44

SS/PBCH

SS(PSS and SSS) and PBCH in NR is transmitted in the same 4 symbol block as specified in the following table.

< Frequency Domain Resource Allocation >

Overall description on the resource allocation for SS/PBCH block is described in 38.211 – 7.4.3.1 Time-frequency structure of an SS/PBCH block and followings are the summary of the specification.

  • SS/PBCH block consists of 240 contiguous subcarriers (20 RBs)
  • The subcarriers are numbered in increasing order from 0 to 239 within the SS/PBCH block
  • The UE may assume that the contents(value) of the resource elements denoted as ‘Set to 0’ in Table 7.4.3.1-1 are set to zero. (This mean that the contents of the gray colored resource element in the SSB diagram shown below is filled with zeros).
  • k_ssb corresponds to the gap between Subcarrier 0 of SS/PBCH block and Common Resource Block 
    • is obtained from the higher-layer parameter OffsetToPointA
    • offset-ref-low-scs-ref-PRB corresponds to the FrequencyInfoDL.absoluteFrequencyPointA. Data type is ARFCN-ValueNR and the range of the value is INTEGER (0..3279165) in integer.
  • There are two types of SS/PBCH Block
    • Type A (Sub 6)
      • k_ssb(k0 in older spec) = {0,1,2,…,23}
        • 4 LSB bits of k_ssb value can informed to UE via ssb-subcarrierOffset in MIB
        • The MSB bit is informed to UE via a bit within the PBCH Data ()  
        • is expressed in terms of 15 Khz subcarrier spacing
      • u (numerology) = {0,1}, FR1 (sub 6 Ghz)
      • is expressed in terms of 15 Khz subcarrier spacing
    • Type B (mmWave)
      • k_ssb(k0 in older spec) = {0,1,2,…,11}
        • the whole k_ssb value can be informed to UE via ssb-subcarrierOffset in MIB
        • is expressed in terms of the subcarrier spacing provided by the higher-layer parameter subCarrierSpacingCommon in MIB  .
      • u (numerology) = {3,4}, FR2 (mmWave)
      • is expressed in terms of 60 Khz subcarrier spacing

NOTE : Actually understanding k_ssb and  in the resource grid often get confusing and hard to visualize. The following is an example where the SubcarrierSpacingCommon is equal to 30KHz, and k_ssb=2, where in such a case the center of the first subcarrier of the SS/PBCH Block (which has 15KHz SCS) coincides with the center frequency of the subcarrier 1 of    

5G NR Frame

This table can be represented in Resource Grid as shown below. Note that the position of PBCH DM-RS varies with v and the value v changes depending on Physical Cell ID.

5G NR Frame

< Time Domain Resource Allocation >

Following table indicates the first OFDM symbol number (s) where SS/PBCH is transmitted. This is based on 38.213 – 4.1 Cell Search.

The document states as follows :

  • For a half frame with SS/PBCH blocks, the number and first symbol indexes for candidate SS/PBCH blocks are determined according to the subcarrier spacing of SS/PBCH blocks as follows.

This means that [38.213 – 4.1 Cell Search] specifies SS/PBCH location in time domain as illustrated below.

5G NR Frame

< Start Symbols for each subcarrier spacing and frequency >

5G NR Frame

Followings are examples of SSB Transmission for each cases. For the simplicity, I set the frequency domain location of SSB block to be located at the bottom of the system bandwidth, but in reality the frequency domain location can change to other location (e.g, center frequency of the system bandwidth). The main purpose of these examples is o show the time domain location (transmission pattern) of each cases. In real deployment, it is highly likely (but not necessarily) that the frequency domain location of the SSB located around the center frequency.

The example below shows how you can correlate the above table to the SSB transmission plot shown in the following examples.

5G NR Frame
5G NR Frame

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5G beamforming, beam steering and beam switching with massive MIMO

Beamforming, Beam Steering & Beam Switching with Massive MIMO for 5G compared

Combining the high propagation loss of the millimeter wavelengths (mmWaves) employed in 5G new radio (5G NR) systems, plus the higher bandwidth demands of users, combinations of beamforming techniques and massive Multiple Input and Multiple Output (MIMO) are essential for increasing spectral efficiencies and  providing cost-effective, reliable wireless network coverage.

Beamforming

Beamforming is the application of multiple radiating elements transmitting the same signal at an identical wavelength and phase, which combine to create a single antenna with a longer, more targeted stream which is formed by reinforcing the waves in a specific direction. The general concept was first employed in 1906 for trans-oceanic radio communications.

With more radiating elements that make up the antenna, the narrower the beam. An artifact of beamforming is side lobes. These are essentially unwanted radiation of the signal that forms the main lobe in different directions. Poor engineering of antenna arrays would result in excessive interference by a beamformed signal’s side lobe. The more radiating elements that make up the antenna, the more focused the main beam is and the weaker the side lobes are.

Beamforming, Beam Steering, Beam Switching, Massive MIMO for 5G

Figure 1: Beamforming with two and four radiating elements

While digital beamforming at the baseband processor is most commonly used today, analog beamforming in the RF domain can provide antenna gains that mitigate the lossy nature of 5G millimeter waves.

Beam steering and beam switching

Beam steering is achieved by changing the phase of the input signal on all radiating elements. Phase shifting allows the signal to be targeted at a specific receiver. An antenna can employ radiating elements with a common frequency to steer a single beam in a specific direction. Different frequency beams can also be steered in different directions to serve different users. The direction a signal is sent in is calculated dynamically by the base station as the endpoint moves, effectively tracking the user. If a beam cannot track a user, the endpoint may switch to a different beam.

Beamforming, Beam Steering, Beam Switching, Massive MIMO for 5G

Figure 2: Beam steering and beam switching

This granular degree of tracking is made possible by the fact that 5G base stations must be significantly closer to users than previous generations of mobile infrastructures.

Massive MIMO

Multiple input and multiple output (MIMO) antennas have long been a feature of commercial public wireless and Wi-Fi systems, but 5G demands the application of massive MIMO. To increase the resiliency (signal-to-noise ratio / SNR) of a transmitted signal and the channel capacity, without increasing spectrum usage, a common frequency can be steered simultaneously in multiple directions.

The successful operation of MIMO systems requires the implementation of powerful digital signal processors and an environment with lots of signal interference, or “spatial diversity”; that is a rich diversity of signal paths between the transmitter and the receiver.

Massive MIMO for 5G

Figure 3: Multiple input and multiple output (MIMO)

Diversity of arrival times, as the signal is bounced from different obstacles, forms multiple time-division duplexing (TDD) channels that can deliver path redundancy for duplicate signals or increase the channel capacity by transmitting different parts of the modulated data. First conceived of in the 1980s, there are a few differences between classic multi-user MU-MIMO and Massive MIMO, but fundamentally it is still the large number of antennas employed and the large number of users supported. The degree of MIMO is indicated by the number of transmitters and the number of receivers, i.e. 4×4.

Conclusion

Beamforming, Beam Steering, Beam Switching and Massive MIMO are key ingredients for 5G base stations.

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Safety of 5G Frequencies and Networks

Massive MIMO Beamforming 5G

Is 5G Safe? Why do some people think it isn’t?

There’s currently huge controversy in the news today regarding safety of 5G: Is it safe, or not? 5G vendors & scientists say the technology is perfectly safe, and some members of the public allege that 5G isn’t safe. Here we examine the topics factually.

Frequencies used by 5G

There is nothing magic or new about the frequencies used or proposed for 5G. They have ALL been used already, actually for decades! 5G frequencies are split into two sections: FR1 (less than 6GHz) and FR2 (high frequency microwave, or “millimeter wave”).

Almost ALL of the FR1 frequencies have already been used for 4G, and some before that for 3G, and 2G, back to the 1990’s. A good example is 900MHz (the original GSM system) and 1800MHz (second round of GSM). 2100MHz was used extensively for 3G. A few of the FR1 frequencies haven’t been used for 4G before (e.g. 3800 up to 4200MHz) but they have been used for other purposes before.

FR2 frequencies (millimeter wave, or mmWave) have already been used – very widely – for Point-to-Point microwave links. All of the FR2 bands (24Ghz, 26GHz, 28GHz, 38-40GHz, and even the proposed 60GHz) have been used for point-to-point terrestrial microwave links. Those are the parabolic dishes you see everywhere on rooftops or towers. These signals are highly directional “pencil beams” with typically 1 degree or less beam width. The number of these links globally is in the 100,000+ range: they are beaming signals around cities all over the world, usually connecting internet services, beaming signals up to 3G/4G towers or for links between corporate office networks. As a result of the creation of 5G technology, these frequencies are now being re-used (“re-farmed”) for use by 5G base stations to connect end users to the internet, using Point-to-multipoint beamforming technologies. Important note: the use of 5G is no more or less “scary” than the previous use for point to point links. Note that point-to-point microwave has existed since 1930: 90 years ago, and health risks (and lack of risk to public) are very well understood.

Operating Distances

5G in lower frequencies travels longer distances than higher frequencies, due to laws of physics. This is why the lower frequencies are used for Rural locations for wide area coverage, whereas the higher frequencies are reserved for use in cities, where distances are shorter, and user densities higher.

Also, the lower frequencies (lower end of FR1) can be transmitted at higher power levels than the higher frequencies. Conversely, high frequencies (mmWave, FR2) are limited to lower power due to limitation of today’s commercial technology.

5G in the 24GHz, 26GHz, 28GHz range and above (also called millimeter wave, or mmWave bands) uses higher frequencies than 4G. As a result, these high frequency 5G signals are not capable of traveling large distances (over a few hundred meters), unlike 4G or lower frequency 5G signals (sub 6 GHz) so penetration and hence coverage are lower.
This higher frequency therefore requires placing 5G base stations every few hundred meters in order to use higher frequency bands.

5G and RF power levels

Some of the “5G Conspiracists” allege that 5G will cause damage/health risk to humans. There is simply no measured case or evidence of this happening. If there were, there would be scientists & health advisors demanding change. Let’s examine in more detail:

5G sites using FR1 transmit at exactly the SAME power levels as 4G sites. So you’re not irradiated any more than a 4G site was. 40W a typical figure for a macro (big) site, and 1W for a Small Cell (small site).
Note carefully: 5G FR1 sites use EXACTLY the same power levels as 4G sites, which is similar to 3G sites, and before that, 2G sites …
5G uses “sector antennas” (typically 3 on a macro site) just like 4G does.
Therefore any related health risk is therefore the same for 5G as it’s predecessors.

5G sites using FR2 transmit at MUCH lower power levels: less than 1 Watt typically. These high frequency signals have poor penetration of buildings and obstacles, so are generally “line of sight” only. As noted above, ALL of the FR2 frequencies have been used before, for terrestrial microwave links, and at similar power levels (less than 1 Watt).
The use of beamforming steers the signal to the required locations; this reduces the overall amount of transmitted power emitted into the air, and hence total radiation. Put simply, if you aren’t using your device, the base station doesn’t point power at you.

How to 5G power levels compare to other Radio/RF transmitters?

The VERY good question conspiracists & “truthers” never discuss. Let’s go straight there.

  • A TV transmitter such as Crystal Palace in London, UK currently transmits digital terrestrial Television at over 1200kW (1.2 MEGAWATT, or 1,200,000 watts), and has been transmitting TV since 1956.  That is 120 MILLION TIMES more power than a V-band 60GHz radio, and transmitting for over 60 years.   Did you hear “5G protesters” complaining about TV transmitters? No, because there’s no widespread history of health effects over 60 years .
  • Airport Radars:   To keep planes flying safely, airport radars transmit pulses up to 25kW (25 kilowatts, or 25,000 Watts) into the air, with average power 2.1kW (2100 Watts).  Interestingly, these signals are at similar frequencies to 3G, 4G and 5G.  In the USA, 2.7 – 2.9 GHz is used.  Yet nobody complains about these high power levels of radar, which has been in constant use since the 1930s:  90 years.
  • Digital Radio (DAB): Crystal Palace transmits digital radio with 18kW (18,000 Watts) of radio power. Compare that with 40W of a large (macro) 5G base station.
  • Emergency Service (TETRA) Radios : used by police, fire & ambulances: transmit at up to 45 Watts. Very similar to the 40W of a large (macro) 5G base station.

You will notice that the HIGHEST powered transmitters are Television transmitters (Megawatt), Radars & Radio stations (10’s of Kilowatts). A macro 5G base station at 40W comes nowhere close. Note that these various transmitters are used on different frequencies, there’s no “one” frequency that is safer (or less safe) than another. It’s only the RF exposure (power) level that matters – specifically, the power incident on your own human body.

Why is there no mass hysteria from “Truthers” about TV, Radar and Radio transmitters? Because if they were THAT bad for our health, they would have been banned and switched off decades ago. Evern the largest (macro) 5G transmit powers are tiny by comparison.

Key “Truther” points examined:

  • 60GHz is absorbed by Oxygen in the bloodstream (Untrue)
    Out in the open air this absorption is true : but not in the body! 60GHz signals are 40% reflected by skin surface, absorbed by water (body is 60% water), and does NOT enter the bloodstream. The “Truthers” invent Pseudo-science , claiming: “This causes Oxygen to not bind well to blood hemoglobin causing the body to become Oxygen starved (hypoxia)”  This statement is hopelessly unscientific.  The ultra low power 60GHz signals do not even penetrate human skin.  The signals are partly reflected and partly absorbed by the skin, preventing them entering the body and cannot cause the claimed effect.  There is NO scientific study which will back up this claimed hypoxia effect on the human body.  The “5G protesters” NEVER provide any, because there is no publication or science that would agree with their unscientific claims – it’s simply not impossible. They make stuff up to make you afraid, and sharing their website gives them more “hits”: Some have adverts on their sites. More clicks means more money for them! (Fear=money for some)
  • 5G is a state-sponsored weapon: Untrue.
    5G is simply a marketing term applied to the work of the 3GPP, a standards body which includes equipment vendors & operators, as a linear development of from work that was labelled 4G and 3G before it. Governments are not included in developing 2G, 3G, 4G, 5G… and future 6G technology – corporations are.
  • Governments want to use 5G to control the population: Untrue,
    in that 5G gives Government agencies no more data than 4G does. Your location, digital activities, content & data usage habits are already well known to Google, Facebook and – on warrant – Law Enforcement Agencies. 5G does not change this at all. You already gave all that data to companies 10 years ago when you bought a 3G smartphone, or signed up with Social Media sites, apps, Apple or Google services. Law enforcement agencies can demand access to that data with a warrant.
  • IoT is scary: Untrue, in any way that relates to 5G.
    “Internet of Things” is a marketing label applied to home gadgets – and industrial devices – that are connected via the Internet by either WiFi or cellular (4G, 5G) networks. The same IoT label applies to a WiFi doorbell. Main concern with IoT is DATA security, particularly physical security (locks, cars) and CCTV camera feeds. That has nothing to do with 5G, because the concern is the data security of the devices & security attitudes of companies that sell them. Note that the WiFi-connected IoT devices are a much greater security risk than 4G, 5G because WiFi is much easier for criminals to hack/spoof.
  • 5G causes cancer: Untrue.
    5G uses the same signals as 4G (FR1), plus some millimeter wave frequencies (FR2) which were previously used by microwave links for decades. There is no link to cancer in 30+ years of medical research and continued exposure to these signals. Microwave & radio signals used by 4G & 5G are NON-ionising radiation which is not hazardous except in massively high power levels (far more than 4G, 5G etc). The “dangerous” radiation type is IONISING radiation, including X-rays and similar. Those are not used for communication for this exact reason: they are dangerous.
    (Side-note: X-Rays used in medicine are VERY carefully controlled. Had an X-Ray? note the operators have shielding everywhere, because they use it every day & could get higher does than patients. They regulate the dose to you carefully for your safety)
  • 5G is linked to Coronavirus: Untrue.
    There’s no link at all. Many of the countries with terrible cases of Coronavirus have no 5G. And vice versa. All the theories connecting the two have been soundly debunked by reputable & international scientists.
    (Side note: there IS a link between Coronavirus deaths and air pollution: because the Coronavirus effect on the body attacks the lungs, putting patients with poor respiration are at great risk. Cleaning up diesel emissions, industrial cities & banning smoking would have saved 1000’s of lives from Coronavirus.)

Power levels and Distance (very important topic)

The RF power emitted from the transmitter antenna spreads with distance. This means that a person some distance away from the tower only receives a weak signal. As you DOUBLE the distance, you receive one QUARTER the power level. This is called the “inverse square law”. What it means in practice is that a person 100’s of metres away from a base station is radiated with only microwatts of power, which is insignificant, especially compared to this next point:

The highest radiation of Radio signals you will get is from …. wait for it …
Your cellphone is on your person – and when used in the worst case, held directly against your head. The cellphone transmits at up to 1 Watt power – in all directions – which means the signals go into your head as well as the air around you. This topic remains the same since the first cordless phones in the 1980’s, analogue cellphones and GSM phones in the 1990’s. Using the phone means the signal is close to your head – and the most sensitive item, your brain. The HIGHEST amount of radiation you will receive from any wireless system is from your OWN HANDSET when you hold it to your head to make a voice call. Therefore, if you are really worried about cellphone safety – STOP using your OWN phone. The radiation your body receives from it is 1000’s of times stronger than that you receive from the mast.

If you’re worried about 2G, 3G, 4G, 5G masts: stop now. The FIRST thing you must do is switch off your OWN phone, and never hold it against your head to talk. And if it’s in your pocket/jacket/handbag do remember, it’s still transmitting to the mast, updating it’s location to the network, and often up/downloading data to your apps continually. It’s still transmitting, even in “standby”.
If you’re not prepared to turn off your OWN PHONE, then stop worrying about masts at all. The signal from masts signal is over 1000 times weaker than your OWN PHONE when it reaches your body.

Massive MIMO Beamforming 5G
Diagram courtesy Qualcomm

5G FR2 mmWave Penetration

Also, these higher frequency 5G signals cannot penetrate solid objects easily, such as cars, trees, and walls, because of the nature of these higher frequency electromagnetic waves. 5G cells can be deliberately designed to be as inconspicuous as possible, which finds applications in places like restaurants and shopping malls.

Cell types
5G NR FR2
Deployment environmentMax. number ​of usersOutput power ​(mW)Max. distance from ​base station
FemtocellHomes, businessesHome: 4–8
Businesses: 16–32
indoors: 10–100
outdoors: 200–1000
10s of meters
Pico cellPublic areas like shopping malls,
airports, train stations, skyscrapers
64 to 128indoors: 100–250
outdoors: 1000–5000
10s of meters
Micro cellUrban areas to fill coverage gaps128 to 256outdoors: 5000−10000few hundreds of meters
Metro cellUrban areas to provide additional capacitymore than 250outdoors: 10000−20000hundreds of meters
Wi-Fi
(for comparison)
Homes, businessesless than 50indoors: 20–100
outdoors: 200–1000
few 10s of meters
5G NR mmWave FR2 coverage

Challenges for 5G Safety – for EVERYONE !

5G Networks
5G Networks

It is the responsibility of the 4G/5G cellular industry, national regulators, safety agencies and all academics to be truthful about the safety of all radio transmitters. There must be no cover-ups, lying, or partial truths. Medical research into possible risks of RF exposure must continue and be well funded. The industry needs to deliver reliable cellullar service without putting populations at risk. “Profit” cannot come at cost of public safety.

Conversely – “truthers” making up pseudo-science & invented “facts”, with blogs written by uneducated persons have so far resulted in:

  • Violence and threats against telecom employees doing their jobs on sites
  • 4G/5G sites being burned down (resulting in loss of service to Hospitals, including those treating Coronavirus and critical health conditions)
  • Death threats and threats of violence against business owners.

Now think clearly and rationally: EVERYONE has a legal & moral responsibility to behave within the law and not to threaten the health of others.
Clearly those posting non-factual “truther” content on Internet websites & social medahave a responsibility to bear. If you are one of those authors, think carefully. Your action could well cause harm or death of others.

I simply don’t believe you!

That’s the frequent response of someone when confronted with information that conflicts with their previously held opinion or prejudices. In the case of 5G, we have we have plenty of information sources. On the “5G is safe” side we have:

  • All reputable Scientists Worldwide
  • All national Governments
  • Biologists Worldwide
  • All safety Agencies Worldwide
  • The Cellphone industry
  • 30+ years of no measurable health effects of cellphones on worldwide population

And on the “5G is unsafe” side we have:

  • Conspiracists without facts
  • Non-scientific blog writers, some whom earn $ from adverts on their blogs (!)
  • Narcissists who want “likes” on posts, or TV appearances
  • Easily-swayed but highly opinionated people
  • NO evidence of health effects over 30+ years
  • NO reputable scientists !

Have a careful think about what sources of information you take in forming your world view. Just two hundred years ago, our ancestors burned and drowned innocent people for “witchcraft”. Why are we any better informed than our ancestors? Answer: SCIENCE and EDUCATION. We use logic, rather than irrational and uninformed fear.

Conclusion for 5G & Safety

There is a huge media frenzy and “truther sites” full of pseudo-science about 5G & safety. We suggest we make our decisions based on science and facts. Here’s our summary:

  • 5G is no less safe than 4G. If you didn’t protest 4G, stop protesting 5G.
  • (If you DID protest 4G, then carry on protesting, but remember, 5G is no less safe!)
  • Millimeter wave” frequencies have already been used for 3 decades or more for terrestrial microwave links. We’ve already been irradiated by them for 30+ years, with no harm to us. 5G just re-uses these same frequencies.
  • There is no measured health risk from “Millimeter Wave” signals in any credible study or publication. 60GHz doesn’t stop O2 in the blood, that’s a non-scientific myth invented by “truther” blogs. No medical reports or science to back up claims.
  • “Millimeter wave” (FR2) transmitters are on average 50x less powerful than the lower frequency FR1 macro (main site) transmitters.
  • The HIGHEST radiation you will get is from your OWN cellphone: it’s right next to your body, and transmits even in your pocket/jacket/handbag. If you’re worried, turn it off.
  • Turning off 5G transmitters on masts makes AlMOST NO DIFFERENCE because the 2G, 3G, 4G transmitters on the mast are still transmitting, all at very similar power levels and frequencies, and distance to you is the same. Power levels radiated to your body remains almost unchanged whether you turn 5G on or off.
  • Turning OFF all the cellphone masts will cause deaths. A LOT of them, as your loved ones can’t dial an ambulance, lost persons, persons caught in fires & crash victims can’t call help. Emergency responders also rely on the masts. Conversely, there’s no measured death rate from cellphone masts, in over 40 years of widespread use.
  • LOGIC as well as ETHICS says leave the masts turned on.

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5G Coverage using FR2 mmWave frequencies

Massive MIMO Beamforming 5G

5G FR2 Coverage and Penetration

5G in the 24GHz, 26GHz, 28GHz range and above (also called millimeter wave, or mmWave bands) uses higher frequencies than 4G. As a result, these high frequency 5G signals are not capable of traveling large distances (over a few hundred meters), unlike 4G or lower frequency 5G signals (sub 6 GHz) so penetration and hence coverage are lower.
This higher frequency therefore requires placing 5G base stations every few hundred meters in order to use higher frequency bands.

5G FR2 mmWave Penetration

Also, these higher frequency 5G signals cannot penetrate solid objects easily, such as cars, trees, and walls, because of the nature of these higher frequency electromagnetic waves. 5G cells can be deliberately designed to be as inconspicuous as possible, which finds applications in places like restaurants and shopping malls.

5G mmWave FR2 Penetration and Coverage
Diagram courtesy Qualcomm
Cell types
5G NR FR2
Deployment environmentMax. number ​of usersOutput power ​(mW)Max. distance from ​base station
FemtocellHomes, businessesHome: 4–8
Businesses: 16–32
indoors: 10–100
outdoors: 200–1000
10s of meters
Pico cellPublic areas like shopping malls,
airports, train stations, skyscrapers
64 to 128indoors: 100–250
outdoors: 1000–5000
10s of meters
Micro cellUrban areas to fill coverage gaps128 to 256outdoors: 5000−10000few hundreds of meters
Metro cellUrban areas to provide additional capacitymore than 250outdoors: 10000−20000hundreds of meters
Wi-Fi
(for comparison)
Homes, businessesless than 50indoors: 20–100
outdoors: 200–1000
few 10s of meters
5G NR mmWave FR2 coverage

Challenges for 5G Coverage:

Transmissions in mmWave bands suffer from significantly higher path loss and susceptibility to blockage. In addition, mmWave RF complexity makes meeting the cost and power constraints of mobile devices extremely challenging, which is why mmWave for mobile communications has historically been not feasible—until now. 5G NR mmWave is changing this.

Uses for 5G mmWave

While the initial focus for mobile operators is to quickly expand network capacities by starting deployments of 5G NR mmWave in existing dense urban markets, there are even more opportunities for mmWave beyond traditional macro networks. One area of interest is to bring mmWave indoors to address the exploding demand of fiber-like wireless broadband access in crowded venues, such as convention centers, concert halls, and stadiums. These venues have traditionally been challenged with limited network capacity, thereby constrained with the quality of service (e.g., slow speeds and unreliable connectivity) they can deliver. With mmWave’s significantly wider bandwidth and high spatial multiplexing gains, mobile operators and service providers could rapidly make multi-Gigabit, low-latency connectivity available to a large number of users.

Another exciting opportunity for mmWave is for private indoor enterprises, including offices, shop floors, meeting rooms and more. Imagine having virtually unlimited capacity and fiber-like wireless connectivity for your devices at work, no matter if it’s a smartphone, tablet, laptop, or mobile extended reality (XR). For these indoor deployment scenarios, we have also performed extensive study to show that significant coverage (i.e., >90%) and multi-Gbps median speeds can be achieved simply by co-siting mmWave small cells with existing LTE or Wi-Fi access points.

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CPRI and eCPRI in 5G and open vRAN

5G Band n77 Remote Radio Head (RRH)

CPRI, eCPRI and open vRAN: What’s happening?

Common Public Radio Interface (CPRI) has been around for quite some time. But now, enhanced CPRI (eCPRI) is becoming an important technology to understand for 5G.
 
Before looking in detail at eCPRI, it’s helpful to understand some of the basic topology of the cellular network, which currently uses CPRI.

CPRI, Remote Radio Heads (RRH) in 4G and 5G

5G Band n77 Remote Radio Head (RRH)
5G Remote Radio Head (RRH) with CPRI or eCPRI fibre optic interface

At the outer circle of a cellular network topology, remote radio units (RRUs) are distributed every few miles in cities and suburban areas. These RRUs comprise antennas and also some compute functionality.
 
Fiber runs from a cluster of these RRUs to connect to a more centralized baseband unit. The baseband unit is also sometimes called the “central processing unit.” Baseband units are typically distributed within approximately 10-mile circles for good coverage in populated areas. The connection between the RRUs and the base station is often referred to as “fronthaul.”

eCPRI

CPRI is an interface that sends data from the RRUs to the baseband unit: CPRI is a serial interface, which is a very high-speed connection, a way to translate all those radio signals back to the computing function.

As we go to 5G, the fiber between the RRUs and the baseband unit is going to carry much more traffic, and that makes it more difficult to do a serial interface. Extreme 5G requirements are stretching the limits of fiber bandwidth.

Enter eCPRI, which is a way of splitting up the baseband functions and putting some of that functionality in the RRU to reduce the burden on the fiber.

AT&T is among many carriers that are working on eCPRI. AT&T has made “the world’s first” eCPRI connection for mmWave at its 5G Labs in Redmond, Washington. AT&T made calls testing eCPRI, using systems from both Nokia and Samsung Electronics America.

This opens the door for higher network throughput with less fiber, which will create more efficient mmWave deployments, among other benefits, This is also a significant step in creating an open architecture within the radio access network (RAN).

Vendor lock-in

Another problem with the CPRI interface today is that it has become a proprietary technology.
 
In addition to supporting more bandwidth across fewer fibers, the enhanced CPRI also addresses the proprietary concerns. eCPRI will be an open interface, making it easier for carriers to mix and match vendor equipment for their RRUs and their baseband units.
 
Historically, because each vendor would have its own implementation of CPRI, it became proprietary. This forces carriers to buy both their RRUs and their baseband unit from the same vendor in order for the interface to work. With O-RAN this interface will be open. Carriers such as AT&T who implement eCPRI will be able to run equipment from different vendors, or even generic off-the-shelf equipment.
 
However, existing networks with CPRI installed will most likely remain in place for years to come.

For Further Information

To find out more about CPRI and eCPRI, please Contact Us

RadioMobile for 5G Network Planning

CableFree RadioMobile 5G LTE Coverage Planning example

RadioMobile: Popular software for 5G Network Coverage planning

RadioMobile is a widely-available software package which can be used for 5G Network Coverage planning, including path profiling and clearance criteria, power budgets, choosing antenna sizes and tower heights.

CableFree RadioMobile 5G LTE Coverage Planning example

For website for RadioMobile, please see this link here:

RadioMobile functions

For 5G Coverage Planning, the software package can be configured with the characteristics of your required radio network.

  • Transmit Power
  • Frequency Band
  • Antenna Gain
  • Receiver Sensitivity
  • Antenna heights
  • System losses
  • CPE types and locations

CableFree RadioMobile 5G LTE Coverage Planning example
CableFree RadioMobile 5G LTE Coverage Planning example

Link Budget & Fade Margins

The software enables quick and rapid calculation of link budget and fade margins for any frequency band.

Terrain Database

The software uses the freely available SRTM terrain data which can download “on demand” for calculation of terrain heights.  Combined with LandCover, this enables estimation of trees/forests also.

Line of Sight

The software uses the terrain database to allows quick establishment of available Line of Sight and “what if” adjustment of antenna/tower heights in a 5G radio network design

Radio Fresnel Zone

RadioMobile automatically calculates the Fresnel Zone for any required link, with graphical display enabling quick feasibility and identification of any obstacles to be noted.

Radio Parameters & Network Properties

Any new user to Radio Mobile will have to enter link parameters for the chosen equipment.  This includes transmit power, receive sensitivity and antenna gains.  Some vendors such as CableFree include this data as a planning service with their products

CableFree RadioMobile 5G LTE Coverage Planning example

Radio Mobile: Free to Use

The Radio Mobile software is free to use including for commercial use.  Radio Mobile software is a copyright of Roger Coudé.  The author notes:

Although commercial use is not prohibited, the author cannot be held responsible for its usage. The outputs resulting from the program are under the entire responsibility of the user, and the user should conform to restrictions from external data sources.

For Further information

For More Information about Microwave Link Planning, we will be delighted to answer your questions. Please Contact Us

5G NR: New Radio

5G NR (New Radio) is a new radio access technology (RAT) developed by 3GPP for the 5G (fifth generation) mobile network. It was designed to be the global standard for the air interface of 5G networks.

The 3GPP specification 38 series provides the technical details behind NR, the RAT beyond LTE.

The study on NR within 3GPP started in 2015, and the first specification release was made available by the end of 2017. While the 3GPP standardization process was ongoing, industry had already begun efforts to implement infrastructure compliant with the draft standard, with the expectation that the first large scale commercial launch of 5G New Radio would occur in 2019.

5G NR: 3GPP Release 16 includes 5G definitions
5G New Radio: 3GPP Release 16 includes 5G definitions

Frequency bands

The Frequency bands for 5G New Radio are being separated into two frequency ranges:[4]

Frequency Range 1 (FR1), including sub-6 GHz frequency bands
Frequency Range 2 (FR2), including frequency bands in the mmWave range (20-60GHz)

5G NR:  New Radio Interface

5G NR Development

In 2018, 3GPP published Release 15, which include what is described as “Phase 1” standardization for the 5G NR standard. 3GPP is expected to publish Release 16, which include the “Phase 2” of 5G NR, by the end of year 2019

5G NR Deployment modes

Initial launches will depend on existing LTE 4G infrastructure in non-standalone (NSA) mode, before maturation of the standalone (SA) mode with the 5G core network.

Non-Standalone mode

Non-Standalone (NSA) mode of 5G New Radio refers to an option of 5G NR deployment that depends on the control plane of existing LTE network for control functions, while 5G NR exclusively focused on user plane. The advantage of doing so is reported to speed up 5G adoption, however some operators and vendors have criticized prioritizing the introduction of 5G NR NSA on the grounds that it could hinder the implementation of the standalone mode of the network.

Standalone mode

Standalone (SA) mode of 5G New Radio refers to using 5G cells for both signalling and information transfer. It includes the new 5G Packet Core architecture instead of relying on the 4G Evolved Packet Core. It would allow the deployment of 5G without the LTE network. It is expected to have lower cost, better efficiency, and assist development of new use cases.

For Further Information

Please Contact Us