Smart Telecom Education

Mobile Broadband addresses the human-centric use cases for access to multi-media content, services and data.

The demand for mobile broadband will continue to increase, leading to enhanced Mobile Broadband.

The enhanced Mobile Broadband usage scenario will come with new application areas and requirements in addition to existing Mobile Broadband applications for improved performance and an increasingly seamless user experience. This usage scenario covers a range of cases, including wide-area coverage and hotspot, which have different requirements.

For the hotspot case, i.e. for an area with high user density, very high traffic capacity is needed, while the requirement for mobility is low and user data rate is higher than that of wide area coverage.

For the wide area coverage case, seamless coverage and medium to high mobility are desired, with much improved user data rate compared to existing data rates. However the data rate requirement may be relaxed compared to hotspot.

The peak data rate of IMT-2020, for enhanced Mobile Broadband is expected to reach 10 Gbit/s.

However under certain conditions and scenarios IMT-2020 would support up to 20 Gbit/s peak data rate,

IMT-2020 would support different user experienced data rates covering a variety of environments for enhanced Mobile Broadband.

For wide area coverage cases, e.g. in urban and sub-urban areas, a user experienced data rate of 100 Mbit/s is expected to be enabled.

In hotspot cases, the user experienced data rate is expected to reach higher values (e.g. 1 Gbit/s indoor).

The minimum requirements for peak data rate are as follows:

- Downlink peak data rate is 20 Gbit/s.

- Uplink peak data rate is 10 Gbit/s.

Peak data rate is the maximum achievable data rate under ideal conditions (in bit/s),

which is the received data bits assuming error-free conditions assignable to a single mobile station, when all assignable radio resources for the corresponding link direction are utilized (i.e. excluding radio resources that are used for physical layer synchronization, reference signals or pilots, guard bands and guard times).

Peak data rate is defined for a single mobile station. In a single band, it is related to the peak spectral efficiency in that band.

User experienced data rate is the 5% point of the cumulative distribution function (CDF) of the user throughput. 

User throughput (during active time) is defined as the number of correctly received bits, i.e. the number of bits contained in the service data units (SDUs) delivered to Layer 3, over a certain period of time.

The target values for the user experienced data rate are as follows in the Dense Urban environment:

- Downlink user experienced data rate is 100 Mbit/s.

- Uplink user experienced data rate is 50 Mbit/s.

Area traffic capacity is the total traffic throughput served per geographic area (in Mbit/s/m2).

The target value for Area traffic capacity in downlink is 10 Mbit/s/m2 in the Indoor Hotspot - eMBB

Connection density is the total number of devices fulfilling a specific quality of service per unit area (per Km2).

The minimum requirement for connection density is 1000000 devices per Km2.

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 M.2083

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.

In recent years there have been several views about the ultimate form that 5G wireless technology should take.

There have been two views of what 5G should be:

• Hyper connected view
• and Next generation radio-access technology

Hyper connected view:

This view of the requirements for 5G wireless systems aims to take the existing technologies including 2G, 3G, 4G, Wi-Fi and other relevant wireless systems to provide higher coverage and availability, along with more dense networks. Apart from having requirements to provide traditional services.

A key differentiator would be to enable new services like Machine to Machine, M2M applications along with additional Internet of Things, IoT applications. This set of 5G requirements could require a new radio technology to enable low power, low throughput field devices with long battery lifetimes of ten years or more.

Next generation radio-access technology:

This view of the 5G requirements takes the more technology driven view and sets specifications for data rates, latency and other key parameters.

These requirements for 5G would enable a clear demarcation to be made between 4G or other services and the new 5G wireless system.

In order to meet the industry and user needs, it is necessary to accommodate all requirements within the definition process, ensuring that the final definition meets the majority of users needs.