With the 4G telecommunications systems now starting to be deployed, eyes are looking towards the development of 5th generation or 5G technology and services.
Although the deployment of any cellular system takes many years, development of the 5G technology systems is being investigated. The new 5G technologies will need to be chosen developed and perfected to enable timely and reliable deployment.
The new 5th generation, 5G technology for cellular systems will probably start to come to fruition around 2020 with deployment following on afterwards.
5G mobile systems status
The current status of the 5G technology for cellular systems is very much in the early development stages. Several companies are looking into the technologies that could be used to become part of the system.
In addition to this the standards bodies, particularly 3GPP are aware of the development but are not actively planning the 5G systems yet.
Many of the technologies to be used for 5G will start to appear in the systems used for 4G and then as the new 5G cellular system starts to formulate in a more concrete manner, they will be incorporated into the new 5G cellular system.
5G cellular systems overview
As the different generations of cellular telecommunications have evolved, each one has brought its own improvements. The same will be true of 5G technology.
- First generation, 1G: These phones were analogue and were the first mobile or cellular phones to be used. Although revolutionary in their time they offered very low levels of spectrum efficiency and security.
- Second generation, 2G: These were based around digital technology and offered much better spectrum efficiency, security and new features such as text messages and low data rate communications.
- Third generation, 3G: The aim of this technology was to provide high speed data. The original technology was enhanced to allow data up to 14 Mbps and more.
- Fourth generation, 4G: This was an all-IP based technology capable of providing data rates up to 1 Gbps.
Any new 5th generation, 5G cellular technology needs to provide significant gains over previous systems to provide an adequate business case for mobile operators to invest in any new system.
Facilities that might be seen with 5G technology include far better levels of connectivity and coverage. The term World Wide Wireless Web, or WWWW is being coined for this.
For 5G technology to be able to achieve this, new methods of connecting will be required as one of the main drawbacks with previous generations is lack of coverage, dropped calls and low performance at cell edges. 5G technology will need to address this.
Although the standards bodies have not yet defined the parameters needed to meet a 5G performance level yet, other organisations have set their own aims, that may eventually influence the final specifications.
Typical parameters for a 5G standard may include:
|SUGGESTED 5G WIRELESS PERFORMANCE|
|Network capacity||10 000 times current network|
|Peak data rate||10 Gbps|
|Cell edge data rate||100 Mbps|
|Latency||< 1 ms|
There are several key areas that are being investigated by research organisations. These include:
- Millimetre-Wave technologies: Using frequencies much higher in the frequency spectrum opens up more spectrum and also provides the possibility of having much wide channel bandwidth – possibly 1 – 2 GHz. However this poses new challenges for handset development where maximum frequencies of around 2 GHz and bandwidths of 10 – 20 MHz are currently in use. For 5G, frequencies of above 50GHz are being considered and this will present some real challenges in terms of the circuit design, the technology, and also the way the system is used as these frequencies do not travel as far and are absorbed almost completely by obstacles.
- Future PHY / MAC: This area presents many possibilities from the use of new modulation formats including GFDM, Generalised Frequency Division Multiplexing, as well as FBMC, Filter Bank Multi-Carrier, UFMC, Universal Filtered MultiCarrier and other schemes to the management of the multiple access schemes. All these need to be developed. Higher levels of processing that will be available by the time 5G is launched mean that multicarrier systems will not require to be orthogonal as in the case of OFDM. This provides considerably more flexibility.
- Massive MIMO: Although MIMO is being used in many applications from LTE to Wi-Fi, etc, the numbers of antennas is fairly limited -. Using microwave frequencies opens up the possibility of using many tens of antennas on a single equipment becomes a real possibility because of the antenna sizes and spacings in terms of a wavelength.
- Dense networks Reducing the size of cells provides a much more overall effective use of the available spectrum. Techniques to ensure that small cells in the macro-network and deployed as femtocells can operate satisfactorily are required.
Other 5G concepts
There are many new concepts that are being investigated and developed for the new 5th generation mobile system. Some of these include:
- Pervasive networks : This technology being considered for 5G cellular systems is where a user can concurrently be connected to several wireless access technologies and seamlessly move between them.
- Group cooperative relay: This is a technique that is being considered to make the high data rates available over a wider area of the cell. Currently data rates fall towards the cell edge where interference levels are higher and signal levels lower.
- Cognitive radio technology: If cognitive radio technology was used for 5th generation, 5G cellular systems, then it would enable the user equipment / handset to look at the radio landscape in which it is located and choose the optimum radio access network, modulation scheme and other parameters to configure itself to gain the best connection and optimum performance.
- Wireless mesh networking and dynamic ad-hoc networking: With the variety of different access schemes it will be possible to link to others nearby to provide ad-hoc wireless networks for much speedier data flows.
- Smart antennas: Another major element of any 5G cellular system will be that of smart antennas. Using these it will be possible to alter the beam direction to enable more direct communications and limit interference and increase overall cell capacity.
There are many new techniques and technologies that will be used in the new 5G cellular or mobile telecommunications system. These new 5G technologies are still being developed and the overall standards have not yet be defined. However as the required technologies develop, they will be incorporated into the new system which will be defined by the standards bodies over the coming years.
5G technology timeline
No dates have been set yet for the development of 5G, but a number of companies and organisations have set their own 5G timelines so they can plan ahead.
One major enabler for 5G will be the release of spectrum, and it is anticipated that the new spectrum will be agreed at the World Radio Communication Conference, WRC to be held in 2015. The International Telecommunications Union, ITU is currently at work on the International Mobile telecommunications, IMT spectrum requirements for 2020 and beyond. After WRC-15, ITU will have a clearer path for determining network system and technology requirements.
estimations of the development of 5G technology estimate that the basic research phase will take place until around 2016 and then the standards will be developed between 2016 and 2018. Product development will then be a major activity between about 2018 and 2020, and early deployment will occur around 2020.
(Article first appear at www.radio-electronics.com)