5G Requirement: Performance
The use cases, and vision of the 5G system lead to diverse requirements that the future mobile broadband system will need to meet.
The 5G unified ecosystem will serve both traditional as well as potential new applications like drones, real time video surveillance, mobile augmented and virtual reality, Internet of Things and so on.
5G will have to cope with a high degree of heterogeneity in terms of:
Services: mobile broadband, massive machine and mission critical communications, broader multicast services and vehicular communications.
Device classes: low-end sensors to high-end tablets.
Deployment types: macro and small cells.
Environments: low-density to ultra-dense urban.
Mobility levels: static to high-speed transport.
By accounting for the majority of needs, the following set of 5G requirements is gaining industry acceptance.
- High capacity and user-rates
- Low latency
- High reliability
- Ubiquitous coverage
- High mobility
- Massive number of devices
- Low cost and energy consumption
One of the key issues with the 5G requirements is that there are many different interested parties involved, each wanting their own needs to be met by the new 5G wireless system.
This leads to the fact that not all the requirements form a coherent list.
No one technology is going to be able to meet all the needs together.
As a result of these widely varying requirements for 5G, many anticipate that the new wireless system will be a umbrella that enables a number of different radio access networks to operate together, each meeting a set of needs.
As very high data download and ultra low latency requirements do not easily sit with low data rate and long battery life times, it is likely that different radio access networks will be needed for each of these requirements.
Accordingly it is likely that various combinations of a subset of the overall list of requirements will be supported when and where it matters for the 5G wireless system.
ITU-R has defined the following main usage scenarios for IMT for 2020 and beyond in their Recommendation, ITU-R M.2083:
Enhanced Mobile Broadband (eMBB) to deal with hugely increased data rates, high user density, and very high traffic capacity for hotspot scenarios as well as seamless coverage, and high mobility scenarios, with still improved used data rates.
Massive Machine-type Communications (mMTC) for the IoT, requiring low power consumption, and low data rates for very large numbers of connected devices.
Ultra-reliable and Low Latency Communications (URLLC) to cater for safety-critical, and mission critical applications which requires different key capabilities according to ITU-R M.2083.
So 5G should deliver significantly increased operational performance, such as increased spectral efficiency, higher data rates, low latency, as well as superior user experience (near to fixed network but offering full mobility and coverage).
5G needs to cater for massive deployment of Internet of Things, while still offering acceptable levels of energy consumption, equipment cost and network deployment and operation cost. It needs to support a wide variety of applications and services.
- Peak data rate: Maximum achievable data rate under ideal conditions per user or device. The Peak data rate is expected to reach 20 Gbps, under certain conditions and scenarios.
- User experienced data rate: Achievable data rate that is available ubiquitously across the coverage area to a mobile user or device. In urban and sub-urban areas, a user experienced data rate of 100 mega bit per second is expected to be enabled, In hotspot it is expected to reach higher values (e.g.1gigabit per second indoor).
- Latency: The contribution by the radio network to the time from when the source sends a packet to when the destination receives it. 5G will be be able to provide 1 millisecond over-the-air latency.
- Mobility: Maximum speed at which a defined QoS and seamless transfer between radio nodes which may belong to different layers and/or radio access technologies can be achieved (in km/h). IMT-2020 is expected to enable high mobility up to 500 km/h with adequate QoS.
- Connection density: Total number of connected and/or accessible devices per unit area (per Km2).
- Network Energy efficiency: referring to the quantity of information bits transmitted to or received from users, per unit of energy consumption of the radio access network (in bit/Joule); It should be improved by a factor at least as great as the envisaged traffic capacity increase of IMT-2020 relative to IMT-Advanced for eMBB.
- Spectrum efficiency: Average data throughput per unit of spectrum resource and per cell (bit/s/Hz). It is expected to be three times higher compared to IMT-Advanced for eMBB.
- Area traffic capacity: Total traffic throughput served per geographic area (in Mbit/s/m2). IMT-2020 is expected to support 10 Mbit/s/m2 area traffic capacity, for example in hot spots.