Technology Background

5G New Radio - Chances and USIM/USAT Test Challenges

The realization of 5G in cellular mobile radio will generate an immense number of new business opportunities. Everything from entertainment and sports to medicine, manufacturing, transportation, construction, and education will be affected by 5G.

To achieve this, many changes of the network infrastructure as well as new features supplied by mobile devices are required. Naturally, the introduction of this new network technology will have a significant influence in device testing in general and in 5G USIM/USAT testing in particular.

Cellular Connectivity of Everything

To get not lost in the jungle of new business applications the ITU-R (International Telecommunications Union - Radiocommunication) classified them in their IMT-2020 specifications into three categories:

mMTC targets the type of connections also known from the Internet of Things (IoT). It is characterized by a large number of connected devices typically transmitting a relatively low volume of non-delay-sensitive data. IoT stands for low power wide area (LPWA) secure operator managed networks using licensed spectrum bands for sensing, metering, and monitoring devices. 3GPP specified this network technology starting with release 13 of their core and test specifications, already introducing the terms NB-IoT and LTE Cat M1 within LTE environment.

Mobile IoT applications as well as devices providing mMTC both are typically demanding

  • low manufacturing and operational costs
  • long battery lives
  • operation in remote and hard to reach locations

To achieve a smooth operator migration path to 5G NR frequency bands while preserving NB-IoT and LTE-M deployments 3GPP has agreed that the LPWA use cases will continue to be addressed by evolving NB-IoT and LTE-M as part of the 5G specifications.

eMBB stands for a natural evolution of existing 4G networks addressing human-centric use cases assuring faster data rates and therefore a better user experience than current mobile broadband services. It will provide

  • higher connectivity and coverage
  • higher mobile broadband services in moving vehicles including cars, buses, trains, and planes
  • reduced latency

Apart of the consumption of multimedia content for entertainment purposes there are countless other applications that will benefit from this type of connectivity, as Virtual Reality (VR), Augmented Reality (AR), real-time video monitoring, virtual meetings with 360o video, real-time interaction.

URLLC is a communication service for successfully delivering packets with stringent requirements, particularly in terms of availability, latency, and reliability. They are demanding

  • very high reliability
  • extremely low latency
  • short network traversal time

It addresses primarily services for latency sensitive applications like factory automation, autonomous driving, and remote surgery. These applications require submillisecond latency with error rates that are lower than 1 packet loss in 105.

Performance Targets

The Heterogeneous Requirements of 5G NR Controlled Services

  • High peak data rates
    Transfer rates experienced by the user of up to 1Gbps

  • Seamless mobility
    Uninterrupted service delivery even in airplanes (1,000km/h) and across licensed and unlicensed networks (e.g. Wi-Fi and 5G)
     
  • Near real-time latency transmissions
    Just 1ms to transmit the data packet from one destination to another

  • Very high reliability
    Maximum 1 out of 100 million packets gets lost

  • Ubiquitous connectivity
    To talk to sensors and meters even in the most remote locations

  • High connectivity density
    Allows one million connections per km²

  • Long battery life
    Energy-efficient IoT devices that are very sporadically active (staying asleep even for several days) can be powered by one battery for up to 10 years

  • Low costs
    Integration into low-cost (consumer) products requires cost efficiency with regard to production and operation

 

Adapt the 5G Network Capabilities to the Current Demand

As strange as it sound, 5G is really nor just one technology. The mix of different technologies allow to get just the flavor of speed, number of connected devices per cell, or battery live you need for your application. Draw a circle spanned by all achievable 5G performance characteristics. One 5G device may require ultra-reliable services, whereas another one may need ultra-high-bandwidth communication or extremely low latency. Determine what you want to achieve, or what your customers expect in terms of performance and put a dot within this circle. Starting from there it is easy to determine what infrastructure is required to offer a top user experience for your customers. It is the big challenge of 5G to enable the coexistence of this very heterogeneous services within the same physical Radio Access Network (RAN) architecture.

Figure: Use case specific requirement maps within 5G

5G Frequency Bands

To cope with the requirement of providing simultaneously coverage and capacity 5G can broadcast in following frequency bands:

  • Low frequency band (sub 1 GHz)
    Coverage Layer to allow traditional coverage applications and new specific usages such as Internet of Things (IoT), Industry Automation, and Business Critical use cases.
  • High frequency band (1 GHz to 6 GHz)
    This layer delivers the best compromise between capacity and coverage.
  • Very high frequency band (above 6 GHz)
    “Super Data Layer" to address specific use cases requiring extremely large capacity and high throughput hotspots.

Network Slicing

The technology used to meet the diverse requirements at the same time within one network is called network slicing. It allows an intelligent allocation of the network computing, storage, and communication resources among the active services with the aim of guaranteeing their isolation and given performance levels. It is achieved by running multiple logical networks as virtually independent operations on a common physical infrastructure. This way a 5G network can adapt to the external environment rather than the other way around.
Standards for slicing are not complete yet, but network slicing technology is maturing rapidly, so that commercial deployments are anticipated latest end of 2020.

COMPRION pushes USIM/USAT Conformance Testing

The Subscriber Identity Module (SIM) has been authenticating secure access to the mobile network up to now and it will do so also under 5G, irrespective of whether the SIM is implemented on a UICC or eUICC. Therefore comprehensive conformance and interoperability testing will be as indispensable as it is.  As already mentioned, standardization of the core technology as well as of the test procedures is still on the way for 5G. The GCF Steering Group, however, has recently approved the elaborated work item proposal for USIM/USAT Interworking with 5G.

COMPRION’s participation in relevant standardization bodies gives us an edge when it comes to preparing the ground. Just like with LTE and legacy cellular technologies, we are early in the market because of our cooperation with network simulator vendors. We have already implemented the needed core spec changes and will soon present a 5G USIM/USAT test solution at GCF and PTCRB. COMPRION contributed to the recently approved CT6 work item for 5G, and the rapporteurship of this work item has been assigned to COMPRION.

Among the great number of different options for network operators to migrate from LTE to 5G, standardization for USIM/USAT testing starts with the version where both, core network and base stations, use 5G technology. The main scope of testing will be the interworking of 5G enhancements for 3GPP TS 31.102 and 3GPP TS 31.111 together with the new 5G core network.

Roadmap

COMPRION submitted already the test cases work plan that was approved by the 3GPP CT Working Group 6. The work plan proposes the introduction of test cases to TS 31.121 on key topics when the access is performed over a 3GPP access Network. In the next CT6 meeting the draft of first test cases is expected to be approved. This will pave the way for assigning the test cases to the GCF work item in April, 2019.

Please keep me posted when you have any news regarding this topic!