LTE-Advanced – arriving sooner than you think

Renuka Bhalerao, Senior Product Line Manager, Radisys
Renuka is a Senior Product Line Manager for Radisys Corporation, with her primary focus on 3G and LTE small cell technologies and Trillium software. Prior to this, Renuka held a position of principal systems architect in a customer-facing role specialising in telecom software and systems. Renuka has 17 years of telecom industry experience with expertise in wireless and VoIP solutions.

U.S. operators will lower their spending on LTE networks as initial deployments are completed through 2014, according to a recent report by Technology Business Research. However, while those initial rollouts will solve some immediate network issues, carriers will continue to seek other routes to boost capacity and coverage as the relentless consumption of data continues. Some carriers are already looking to LTE-Advanced (LTE-A) to fulfil these anticipated needs, but its initial deployment will be very different from that of “basic” LTE.

LTE-A, the next upgrade for LTE networks, represents true ‘4G’ – when measured by the original International Telecom Union standards. LTE-A promises to deliver upwards of 1Gbps peak downlink data rates, enhanced cell edge performance, much improved radio interference mitigation and spectrum re-use. The advantages of LTE-A will ensure the technology gains rapid market traction in the U.S. and Europe. However, there are differences between LTE-A and LTE; and especially in their deployment. LTE is being deployed by operators as a complete network upgrade, but LTE-A will be rolled-out by operators incrementally on a feature-by-feature basis. Initially, operators will look to leverage the features of LTE-A that gift them the greatest tactical, and operational, advantages in the market.

Small cells are playing a role in global 3G and LTE deployments and will underpin the key features of LTE-A as well. This is because small cells take the pressure off the macro network by providing traffic offload, coverage and capacity gains. However, mitigating for radio interference in these deployments has always been an issue for operators. It is a challenge that operators are very focused on solving. As operators deploy small cells in the same spectrum as macro cells, the result is the newer small and the older macro cells suffering from radio interference – damaging the overall throughput and capacity of the wireless network. But LTE-A comprises a key radio interference management feature called Enhanced Inter-Cell Interference Coordination (eICIC). eICIC acts to improve the coordination between the network cells and to reduce radio inference and this results in improved network throughput. Case in point, operators in Asia, where LTE arrived in the market much earlier, experienced these interference problems in their roll-outs of LTE. They have turned to commercial LTE-A deployments to mitigate for radio interference in close proximity deployments of small cells in the network.

As well as radio interference mitigation via eICIC, another feature in LTE-A which acts to boost network throughput is carrier aggregation. This feature enables an operator to conduct contiguous and non-contiguous spectrum allocations. This basically means a carrier can ensure their existing spectrum is efficiently aligned to deliver higher network throughput. Increased throughput has usually required more spectrum – which is scarce and extremely costly for the operator – but carrier aggregation removes this requirement for more spectrum to drive higher throughput by leveraging the non-contiguous chunks of available spectrum. Another feature within LTE-A that operators are keen to leverage to improve spectral efficiency is Multiple Input and Multiple-Output (MIMO). A form of smart antenna technology, MIMO involves the use of multiple antennas at both the transmitter and receiver to improve spectral performance.

Combined with efficiencies in radio interference mitigation and spectrum performance, LTE-A also enables an operator to leverage the benefits of Self Optimising Networks (SON). A much discussed feature of LTE-A, SON enables operator’s network to auto-configure network nodes. This allows the network to automatically configure, monitor, and optimise, newly installed network cells and for faulty cells to be repaired.

The features of LTE-A enable an operator to boost network performance and process traffic in a more cost effective way – just as LTE does. However, operators are leveraging their experience of LTE network deployments and making more affordable and efficient incremental deployments of LTE-A delivering gains one-by-one as they are needed.

To hear first-hand more about what steps telecoms companies are making in LTE Advanced, be sure to book your place at the LTE World Summit, the premier 4G event for the telecoms industry, taking place on the 24^th-26^th June 2013, at the Amsterdam RAI, Netherlands. Click here to download a brochure for the event.