Three key development areas in 5G
The continuing growth in demand from subscribers for better mobile
broadband experiences is encouraging the industry to look ahead at
how networks can be readied to meet future extreme capacity and
performance demands. Nokia, along with other industry partners,
believes that communications beyond 2020 will involve a combination
of existing and evolving systems, like LTE-Advanced and Wi-Fi,
coupled with new, revolutionary technologies designed to meet new
requirements, such as virtually zero latency to support tactile Internet,
machine control or augmented reality.
5G will be the set of technical components and systems needed to
handle these requirements and overcome the limits of current systems
Unlike 2G, 3G and 4G, it is unlikely that 5G will be a single new Radio
Access Technology (RAT) nor will it replace macro cells. It will be a
combination of existing RATs in both licensed and unlicensed bands,
plus one or more novel RATs optimized for specific deployments,
scenarios and use cases. In particular, Nokia has identified the need
for a new RAT for ultra-dense deployments, with the aim of providing
a virtual zero latency gigabit experience.
Nokia is already undertaking extensive research to map out the scope of 5G and has a clear vision of the three key pillars that will make this future network a reality
Nokia is already undertaking extensive research to map out the scope of 5G and has a clear vision of the three key pillars that will make this future network a reality
1. More spectrum must be pressed into service
More radio spectrum for mobile networks is vital to meet the
increased capacity and coverage demand. New spectrum will need to
be allocated and put into use quickly. Without sufficient spectrum,
communities beyond the reach of wired broadband will miss out on
the benefits of future services and entire countries could lose ground.
The amount of spectrum available needs to be expanded by adopting
new frequency bands and by using available spectrum more efficiently,
both in terms of frequency and with regard to when and where it is
employed.
2. Networks will become much denser with many more cells
The second pillar of 5G will be to use many more base stations,
deployed in a heterogeneous network (HetNet), combining macro
sites with smaller base stations and using a range of radio
technologies. These will include LTE-A, Wi-Fi and any future 5G
technologies, integrated flexibly in any combination.
3. Raising the overall performance of networks
The third major goal will be to get the best possible network
performance by evolving existing radio access technologies and
building new 5G wireless access technologies. For example, it is
generally accepted that latency must decrease in line with rising
data rates.
Sustained research and development in these three areas will be
necessary to create a 5G environment that can meet market demands
such as 10,000 times more traffic, virtually zero latency and a much
more diverse range of applications. What’s more, all this must be
achieved at an affordable cost to enable operators to maintain and
improve their profitability.
The Nokia vision is that: “5G will enable a scalable service experience
anytime and everywhere and where people and machines obtain
virtual zero latency and gigabit experience where it matters”.
Let’s now look at each of the three development areas in more detail.
Bridging the spectrum gap with 5G
Networks to become denser with small cells
Network densification is needed to meet the throughput and latency
demands likely to arise in 2020 and beyond. By 2020, small cells
are expected to carry a majority of traffic with overall data volume
expected to grow up to 1,000 times (compared to 2010). Nokia’s
analysis shows that sufficient network capacity at a minimum downlink
user data rate of 10 Mbit/s can be achieved using a LTE heterogeneous
network configuration (LTE, small cells and well integrated Wi-Fi), which
is how networks are expected to evolve until 2020.
Beyond this date, a new approach will be needed to achieve ultra-dense small cell deployments and this is where we expect to see innovative 5G components emerging. Whether deployed in ‘traditional’ frequencies (<6 GHz) or in new centimeter and millimeter wave bands, these new technology blocks will need to enable ultra-low latency, higher data rates (peak rates exceeding 10 Gbps, with user data rates greater than 100 Mbps even under high load conditions or at the cell edge) and more flexibility, for example in backhaul or duplexing schemes.
The key to meeting these requirements is to bring the access point closer to the user, with smaller cells making more radio resources available to active users. This will also substantially reduce the radio round trip time for lower latency and increase overall network efficiency by creating sub-networks to handle a proportion of the traffic locally.
The increase in achievable data rates for 5G (10,000 times more
traffic) cannot be achieved without reducing the cell size and
increasing the frequency re-use rate. This is already happening today,
especially for indoor traffic that is inefficient to handle with outdoor
macro cells. Over the next few years this trend will accelerate as
the use of data-hungry applications rises. Ultimately, the need for
small-cell-optimized RAT will be one of the triggers for 5G.
New applications will require ultra-low latency to support online
gaming, augmented reality and to control uses such as tactile
Internet and remote surgery. It is clear that the need for low latency
will become much more important in the future and will need to be
addressed. New, small-cell-optimized RAT for 5G can deliver latency as
low as 1ms.
The mass roll out of IPv6 and the emerging ‘Internet of things’ will lead to more connected devices and also new use cases for small cell deployments. 5G will use some IP mechanisms (e.g. IPv6 Neighbor Discovery Protocol) to simplify the creation of sub-networks that will handle some traffic locally, while autonomous deployment mechanisms, such as mobility and traffic steering, will make roll out more efficient.
With such an increase in access point density there will be ongoing development of interference coordination schemes for data offload from bigger to smaller node types and resource usage coordination between nodes. With many different equipment types and devices, HetNets will have a wide range of performance demands, making self-aware networks essential.
The mass roll out of IPv6 and the emerging ‘Internet of things’ will lead to more connected devices and also new use cases for small cell deployments. 5G will use some IP mechanisms (e.g. IPv6 Neighbor Discovery Protocol) to simplify the creation of sub-networks that will handle some traffic locally, while autonomous deployment mechanisms, such as mobility and traffic steering, will make roll out more efficient.
With such an increase in access point density there will be ongoing development of interference coordination schemes for data offload from bigger to smaller node types and resource usage coordination between nodes. With many different equipment types and devices, HetNets will have a wide range of performance demands, making self-aware networks essential.
Network performance
With 5G, a range of performance measures will become more
important – a multitude of applications and different use cases need
to be addressed, with novel technologies for each specific case to
ensure the limitations of mobile communications systems don’t limit
the overall development of the technology.
In particular, it is not economically feasible to build ultra-dense
networks everywhere and it must be accepted that a virtual zero
latency gigabit connectivity will only become available “where it
matters”. Therefore, while ‘traditional’ performance indicators, such
as peak data rates, will improve, the key to 5G will be flexibility and
support for new use cases.
More important than just peak data rate or spectral efficiency will be
enabling the same 5G system (integrated from different radio access
technologies including new ones) to support requirements such as:
• Few devices demanding huge downloads
• Ultra-high numbers of sensors sending just small data packages
• Remotely-controlled robot applications (low latency needed for
control)
sending back UHD video (high upload capability required).
The scalable service experience in 5G will be all about tailoring the
system to extremely diverse use cases in order to meet specific
performance requirements. A uniform service experience can still
be achieved in most use cases by tighter coupling between RAN and
transferred content, for example, making APIs between the application
and network layer to adjust application demands or by caching data
locally. Furthermore, local sub-networks can be set up, where several
devices create a high performing direct connectivity within a local area.
The key performance measures that will need to be met include:
Round Trip Time (RTT)
Ultra-low latency will be a key aspect of 5G communications systems
because we are moving towards the era of the tactile Internet where
wireless communications will be increasingly used for distributed
control rather than merely content distribution. Also it is predicted
that the maximum data rates per device will increase substantially
faster than Moore’s law, meaning that if the cost of, for example,
HARQ buffers at the device side is to be kept constant, any increase
in air interface bandwidth must be complemented by a decrease in air
interface latency.
The target RTT for 5G is likely to be lower than 1 ms to provide a
virtual zero delay experience and to facilitate a new palette of time
critical Machine Type Communications (MTC).
Spectral efficiency
We will still see improvements and demanding requirements for
spectral efficiency in terms of average bit/s/Hz/cell for ultra-dense
deployments. However, this will probably not be as important as in
the past for the design and optimization of 3G and 4G radio access
technologies, which were mainly optimized for wide area deployments.
Using higher frequency bands, large transmission bandwidth
combined with low transmit power automatically limits the coverage.
What matters more for the new radio access design is the total
deployment cost in terms of cost/area considering a certain traffic
density and a typical experienced user data rate.
Low power consumption
Nokia believes that power consumption for mobile networks must
be kept to a minimum. Low power consumption is also essential for
battery operated terminals to prolong time between battery charges.
Many new potential MTC use cases are more limited by a power hungry
radio access than the offered data rate or latency.
Ultra-low cost per access node
As networks become denser, it is of utmost importance that the
cost per access node is reduced substantially, with an OPEX virtually
close to zero. This means that 5G will have to be fully “plug and
play”. Therefore, the radio access technology needs to be fully autoconfigured
and auto-optimized, and any hierarchy or relation between
network entities, for example, to centralize or distribute radio resource
management, has to be fully self-establishing.
Higher layer protocols and architecture
The Internet of things will greatly multiply the number of connected
devices and this connectivity will be heterogeneous. The adoption
of IPv6 is accelerating and the protocol will probably have become
mainstream by 2020 after which 5G will be launched. Ethernet
is another technology becoming more widespread. “Ethernet
over Radio” could become a simple and cost-effective solution to
encompass 5G HetNets.
No comments:
Post a Comment
If You have any concern you are free to message/comment me.