Philomena Skeffington

Philomena Skeffington, principal consultant in the Information, Communication and Media division at telecoms consultancy, Mott MacDonald Schema

While 2008 was the year of the smartphone device as handheld technology increased exponentially in capacity to wow and amaze, 2009 may be the year of new transport technologies. Here, Philomena Skeffington, principal consultant in the information, communication and media division at telecoms consultancy, Mott MacDonald Schema, takes a look at the world of LTE and WiMAX.

Both long term evolution (LTE) and its competing technology, worldwide interoperability for microwave access (WiMAX) look set to go head to head in the race to enhance customer experience and underpin new and innovative services for mobile users. While they appear to be competitive technologies, LTE and WiMAX share many attributes working on a standard IP core network, for example. Indeed, they could underpin similar mobile applications, like video, and should be seen as complementary rather than competitive standards.

In isolation or in conjunction, WiMAX and LTE promise a new level of user experience. For example, consumers could benefit from a truly untethered broadband experience tapping into video, music and other services without the constraints of location or form factor.


LTE and WiMAX bite fixed pie

The demand for ever higher speed broadband services has pressurised the mobile industry into seeking ways to provide more Mbps over each MHz of spectrum. Both LTE and WiMAX use orthogonal frequency-division multiplexing (OFDM), a transmission technique which optimises use of the finite radio spectrum. Advanced antenna techniques such as multiple-input/multiple-output (MIMO) can double throughput. Additionally installing three to four sectors within a cell can quadruple the base station throughput.

The current generation of WiMAX technology can provide 46 Mbps per sector, whilst the next generation and LTE will provide up to 100 Mbps per sector. This is sufficient to allow, for example, a triple play solution in the rural area, opening these regions up not just for leisure activities but for smaller businesses and entrepreneurs who need no longer be disadvantaged alongside their city-dwelling peers.

WiMAX is arriving just in time to take advantage of the new smaller, cheaper laptops. Handbag-sized devices in various flavours will be used by professionals to access corporate information and emails and by consumers who want flexible connectivity on the go. Technology advances coupled with more sensible mobile broadband price plans will allow everyone to be online wherever we go and for whatever reason.

It should come as no surprise that the trend in broadband data is for increased nomadic and mobile services. This pitches the wireless operators against the fixed broadband operators in a head to head battle. By definition a nomadic service can always substitute a fixed service, but the same is not true in reverse.


LTE complements WiMAX

WiMAX is a technology which has been specifically developed to support data services, although it can also support voice. LTE on the other hand is optimised for voice services, having a latency of less than five microseconds, and can also support data.

It is easy to see how the two technologies may be used in isolation or in tandem. A combination of WiMAX and LTE can provide the whole portfolio of services that a consumer or business might want using each technology to best effect to provide the services it does best. An operator could choose to major on data services or voice services rolling out a WiMAX or LTE network respectively.

A mobile voice operator may choose to rollout LTE as a migration to 4G, reasoning that although investment is needed in new base stations and a new IP core that the mobile handsets will be backwards compatible with 3G and 2G, thus allowing the operator to pace the roll-out of the network upgrade to control its own cash flow.

A nomadic broadband operator may choose WIMAX, reasoning that the ready availability of WiMAX devices in laptops and ultra-portables removes a significant barrier to entry for its customers, whilst providing the mobility that is increasingly demanded in this market. Alternately an operator may choose to roll-out a mixture of WiMAX and LTE.

These access layer technologies both operate over an IP core, and it is possible to configure two types of access network into a single core. This allows the operator to optimise core network costs whilst simultaneously maximising quality of service (QoS) offering, through a more tailored access technology applied on a per market basis. This presents some interesting possibilities in terms of the flexibility in addressable markets and support for MVNOs and multiple application providers, over what is essentially a single network.


Multiple choice question

Today’s 3G phones are still relatively expensive. Emerging markets and bottomof- pyramid markets can barely afford these. 4G phones with their backward compatibility with 3G and 2G are also likely to be expensive but are essential for high end business users who need to be connected, largely by voice, but with some access to data and emails. LTE will be the technology of choice for this niche.

The advent of the cheaper PCs with WiMAX devices ushers in a new era of the cheap mobile internet device. This will suit people who mostly need data or text access. The mobile subsidy model applied to these devices may even support bridging the digital divide as small laptops become available as part of a subscription.


Underserved markets

There are many markets which are not served, or are served badly. Current billing mechanisms favour high data rate users at the expense of low data rate users. Organisations that may have a very high availability requirement may not be catered for on existing networks and are often forced to build their own networks or to use bespoke technology adding extra cost to their operations.

Rural areas are often served poorly by both fixed broadband and mobile operators, and this is directly related to lower revenue and higher cost to serve.


Businesses often purchase

interconnectivity between offices, mobile connectivity and increasingly connectivity to homes to support teleworking. A mixture of WiMAX and LTE can be used to provide voice and data connectivity for employees based in the office or at home. This allows organisations to simplify the number of contracts for communications services thus enabling them to spend more time on applications and to save costs.

Building for the future

Existing investment in mobile tower infrastructure could be used to construct a national WiMAX or LTE network with additional towers where necessary. Remote control of antennas will allow multiple operators to work side by side opening up the possibility of new business models and shared spectrum usage for example.

Furthermore, there’s no reason why a single site cannot accommodate multiple cells and both LTE and WiMAX, thus enabling the spectrum use to be optimised. This could hold the solution to delivering broadband access to the badly served rural locations. The same antennas can be used at certain times for mainly consumer broadband access and at other times for business applications like smart metering for water or gas, or remote network access for small businesses and teleworkers.

A more intelligent world needs more flexible connectivity. As our need for greater control over industrial processes and our hunger for knowledge of environmental impacts grows, we need to collect data from more and more places, some of them extremely remote.

Take, for example, the requirement for monitoring water levels in secluded reservoirs where it’s difficult to build and maintain wires to carry data. Whilst the data rate might not be very high with a cell supporting a low capacity, maximum coverage could, however, be provided. The same cell might support emergency services and a best efforts service to a local farm or other rural dwelling. The openness and flexibility of the technology can be leveraged across markets in a way that was previously unimaginable.

Other applications for WiMAX could include video and CCTV. WiMAX can be configured to optimise uplink or downlink thus putting it ahead of its fixed rival DSL. By its very nature, because it is a mobile technology a range of applications including CCTV or even news-gathering services could utilise WiMAX depending on location. WiMAX could allow flexible monitoring of our homes, changing crime hotspots or largescale events such as festivals or football matches.


Changing times

Even in their own right WiMAX and LTE offer a plethora of opportunities for mobile operators both for existing and new services. But taken together they could offer a whole lot more to consumers, workers and public sector service companies. Understanding where cost savings can be made and new business models can be developed will the key to unlocking the potential of these exciting new technologies.