Interview: Director, radio access network development, NTT Docomo: “Improvements in backhaul will be essential to meet the increasing requirements of the market in the future.”

Takehiro Nakamura, director of radio access network development for NTT Docomo

Takehiro Nakamura, director of radio access network development for NTT Docomo, Japan is speaking in ‘The Future of LTE’ track on Day Two of the LTE World Summit, the premier 4G event for the telecoms industry, taking place on the 24th-26th June 2013, at the Amsterdam RAI, Netherlands. Ahead of the show we learn about how NTT Docomo is taking a lead in the development of LTE, with many of its home-grown technologies forming part of the latest 3GPP LTE standards.

When will you start trialling carrier aggregation and will you introduce it before the rest of LTE-Advanced’s other features?

Docomo has started to develop base stations utilising our own technology — advanced Centralized RAN (C-RAN) architecture for LTE-Advanced. These high-capacity base stations are capable of carrier aggregation and HetNet/eICIC, which will make them ideal for high-traffic areas such as train stations and large commercial facilities. These will be available around 2015.

Will the RAN enhancements that you’re planning for LTE Advanced also need improvements in backhaul?

Optical backhaul has been put to good use in urban and suburban area of Japan already and these will also be used for our high-capacity base stations. However, improvements in backhaul will be essential to meet the increasing requirements of the market in the future.

How are your plans progressing around VoLTE and RCS?

Commercial VoLTE service is under development at NTT Docomo, but no clear deployment plan has yet been decided.

How advanced are your small cells plans and what’s your strategy for integrating them into your network?

Our advanced C-RAN architecture will enable small cells (so-called “add-on cells”) for localised coverage to cooperate with macro cells that provide wider area coverage. This will be achieved with carrier aggregation technology, one of the main LTE-Advanced technologies standardised by the 3GPP. The add-on cells will significantly increase throughput and system capacity, while maintaining mobility performance provided by the macro cell. These add-on cell can be upgraded to improve mobility performance and other aspects, and these improvements are under standardisation for 3GPP Release 12, using the name “Phantom cell” – a concept proposed by Docomo.

The LTE World Summit, the premier 4G event for the telecoms industry, is taking place on the 24^th-26^th June 2013, at the Amsterdam RAI, Netherlands. Click here to download a brochure for the event.

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.

Asian operators pushing the envelope with LTE Advanced

While many parts of the world are awaiting LTE, Asian carriers are already moving ahead leaps and bounds by testing LTE Advanced.

Current LTE rollouts are based on Release 8 of the 3GPP standards, while LTE Advanced is based on Release 10, which was standardised in April 2011. Since then, some companies have been working on pre-release equipment, looking to get a jump on the rest of the industry.

Chief of these are equipment vendor Ericsson and SK Telecom, the biggest operator in South Korea with just under 50% market share. The two have got together to test a specific feature of core LTE Advanced technology called Transmission Mode 9. TM-9 is designed to help reduce interference between base stations to maximise signal stability and boost performance.

TM-9 is particularly smart though. It can detect when a mobile device is being used and send a different type of signal that is optimal for a mobile device (variable DM-RS – demodulation reference signals). This maximises the efficient use of the base station and guarantee’s a decent data rate for users. Early results are positive with a claimed 10-15% increase in data rates in locations where there was known inter-cell interference.

One of the best known improvements that LTE Advanced will bring is Carrier Aggregation and here ZTE have been taking strides with the world’s first use of it in a commercial network. This was the Guangdong arm of China Mobile using 20MHz of spectrum and interestingly was performed on a TD-LTE network. Peak download rate? A massive 223Mbps, more than double the peak rates quoted for Release 8 LTE.

TD-LTE also once again comes to the fore in China, having been used for a live TV broadcast – the Xiamen International Marathon beamed to the TV centres of China Central TV and Xiamen TV. The vendor here was NSN, using its SingleRAN platform with Liquid Core EPC.

It all points to a bright future for LTE.

This next evolution of LTE technology is significant as it will meet the speed requirements of what the 3GPP originally dubbed 4G. LTE Release 8 was of course not originally considered to be 4G, but the 3GPP were forced to acknowledge ‘the realities on the ground’ where even DC HSPA 3G was being dubbed 4G by some US carriers. This time round, there’s no doubt, though I suspect it will simply give some the licence to go to market with ‘True 4G’ or some such exaggeration.

If you want to hear more about the latest advances in TD-LTE then be sure to get to the inaugural TD-LTE Summit taking place on the 23^rd-24^th April 2013 at the Fairmont Singapore Hotel, Singapore. Click here to download the brochure

 

LTE North America – What will LTE Advanced bring? (Panel session video)

One of the best things about LTE events is not just the presentations, but the panel sessions. These give the audience an opportunity to hear the views of key figures in the industry on a particular topic and it’s always interesting to get to hear the different views and opinions.

Here are three short clips from the panel discussion on Day One regarding LTE Advanced. With LTE rollouts progressing well from Verizon, AT&T, MetroPCS, U.S. Cellular and Clearwire, thoughts are already turning to what’s next.

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In part one we have we have Krish Prabhu, CTO of AT&T labs, Jesse Hurwitz, global strategy mobile platforms at Google, Daniel Lönnblad, director of technology, Sony Mobile and Ahmad Armand, Staff VP LTE, MetroPCS, with the session moderated by Alan Quayle of Alan Quayle Business & Service Development.

Ahmad Armand of Metro PCS notes that to one of the features of LTE Advanced is its support for 8×8 MIMO, but this will require devices with more antennas. He notes that admittedly only larger devices such as tablets are likely to actually be able to feature this.

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In part two the simple question is once we get LTE Advanced – “Is DSL dead”.

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In part three we had something a bit different – one word answers to specific questions. As you can see, our panellists are somewhat reluctant to stick to the one word answer scheme but listen as Krish Prabhu gets a good laugh for his response to the question, “Will customers still be paying for voice and SMS!”

For more videos from key speakers at LTE North America 2012 be sure to check out our LTE World Series YouTube channel.

LTE’s virtuous circle: LTE to go mass market in 2012?

Arne Schälicke, LTE Product Marketing, Nokia Siemens Networks

This is a guest post from Arne Schälicke, LTE Product Marketing, Nokia Siemens Networks on the growth of the LTE eco-system and the work that NSN is putting it to make it happen.

That fact that the annual LTE World Summit has recently established itself among the top events in the sector has really underlined the importance of LTE in our industry. It’s also a good opportunity to reflect about the LTE market development that we have seen over the recent years.

By April 2012 there were 64 commercially launched LTE networks, 70 per cent more than a year earlier. The last year has also seen the commercial launches of the first TD-LTE networks. The global adoption of both FDD LTE and TD-LTE is not a vision anymore, it’s a fact. Global scale fosters the development of the device ecosystem, which in turn drives subscriber figures. The LTE virtuous circle has accelerated.

The arrival of multiband/multimode USB dongles has enabled operators to migrate their mobile broadband large screen customers to LTE. Subscribers benefit from faster average throughputs and shorter latency times, while the operators can offload their 3G networks, apply new tariffs and hence optimise their ARPU.

For all the aforementioned reasons, LTE data services have started to expand from the premium high-price segment to mid- and entry-level segments, with some operators having already introduced prepaid packages. Also, some international data roaming packages have been introduced, e.g. by TeliaSonera, who launched commercial LTE services more than three years and now provides LTE in many Northern European and Baltic countries.

The launch of LTE smartphones and tablets has since then accelerated subscriber growth tremendously. The publicly available data from NTT DoCoMo, Japan, shows an acceleration of roughly 300 per cent in monthly subscriber uptake following the introduction of LTE smartphones and tablets in autumn 2011. By April 2012, three operators in the US, Japan and Korea had reported more than two million LTE subscribers. LG U+ in Korea has reached an LTE penetration of more than 20 per cent of its total subscriber base.

In short, in 2012 LTE is becoming mass market.

What does the market success of LTE mean for Nokia Siemens Networks? As specialist in mobile broadband, we have been at the forefront of the LTE and TD-LTE commercialisation since the very beginning. Through our partnerships with the leading LTE operators in advanced markets like Northern Europe, Japan and Korea, we have continuously evolved our commercial LTE network systems to deliver superior throughput and lowest latency times in networks.

With a TD-LTE end-to-end solution, including the complete network infrastructure, services and TD-LTE data devices, we have enabled SKY, the largest satellite pay-TV operator in Brazil, to not only enter the local wireless broadband market, but to also be the first to launch commercial 4G services in Latin America. For operators with existing 1800MHz GSM networks we have commercially introduced concurrent operation of GSM and LTE on the same base station hardware module. Telia Denmark uses our concurrent-mode GSM/LTE technology nationwide and has repeatedly been praised for having the best 4G network in the country.

As the LTE market evolves further so are the LTE offerings of Nokia Siemens Networks. Pushing speeds ever higher we have demonstrated LTE-Advanced with data rates exceeding 1.4Gbps using aggregated spectrum of 100MHz on the commercial Flexi Multiradio 10 base station platform.

With increasing LTE smartphone penetration rates and growing LTE network coverage 2012 is also a significant year of VoLTE, with operators like LG U+, Korea, having already announced their VoLTE plans for this year.

And then, as the LTE World Summit 2012 agenda underlines nicely, small cells will play a key role in complementing macro networks to bring better coverage and capacity boost to areas of high demands. Clusters of small cells can provide the capacity needed in mobile broadband network hot zones. With our highly acclaimed Flexi Zone small cell solution, we are proposing a revolutionary new small cell cluster architecture that ensures  small cell capacity really adds to the macro network and does not “tax” the operator’s TCO.