By Julian Bright

Technology innovation appeared thin on the ground at this year’s Mobile World Congress, but the challenge of enhancing performance and capacity by better utilising existing network resources remained a key focus for many network vendors.

There was particular concern over the availability of sufficient spectrum to support the future growth of mobile broadband services, and while tantalizingly close, the commercial readiness of technologies that promise to deliver new efficiencies, such as public small cells, VoLTE, and LTE-Advanced, remains just around the corner.

In the absence of a single, overriding theme, the major infrastructure vendors elected to present their broader visions of the future network as a more fully integrated and flexible resource embracing developments such as Cloud and M2M.

Major vendor presentations

The threat of further consolidation and growing competition continues to focus the attention of the major vendors on strategy, performance and market positioning. According to NSN’s CEO, Rajeev Suri, the market can only support three long-term vendor players. Coming off the back of a strong second half sales performance and the best year financially in the company’s history, Suri cautiously set his sights on a steady 2013, conscious that in a largely flat market the company will find its recent success difficult to sustain.

The vendor’s stated goal is to enable its operator customers to deliver enough capacity to support 1Gb of data per user per day profitably, and Suri delivered an assured and coherent outline of NSN’s mobile broadband strategy following its restructuring, including Liquid Net flexible network capacity, FlexiZone small cell underlay, and LTE-Advanced. He also fleshed out the company’s recent Liquid Applications announcement, which is designed to help operators extend their co-operation with OTT players and application developers by providing real-time user data at the radio base station.

Ericsson, meanwhile, reinforced its message about the need to extend capacity in the macro network before moving to small cells, and to re-iterate the importance of radio planning in a heterogeneous network environment. In a new development, CEO, Hans Vestberg, announced that the company would be launching an LTE broadcast service with Australia’s Telstra during 2013.

Vestberg said that Ericsson will continue to spend $5bn per year on R&D, covering everything from small cell to transport, packet core and SSRs. Outlining the evolution of Ericsson’s Cloud strategy he announced closer network integration into its cloud offering through the introduction of a control layer and service provider SDN. He also unveiled a collaboration with SAP designed to extend Ericsson’s M2M offering on a global scale, and help bring closer the company’s vision of 50 billion connected devices.

Huawei meanwhile introduced its vision of a ‘SoftMobile’ network environment, designed to address what the company believes will be a US$2 trillion market for mobile operators in 2020.

Based on a three-tiered model, the Soft Mobile concept comprises an underlying ‘ocean’ of fluid broadband capacity using technologies such as indoor and outdoor small cells and active antennas, orchestrated and managed at the radio access level through the use of technologies such as Cloud BBU, and providing on-demand service and network resources for vertical enterprise sectors as well as the traditional mobile market.

TD-LTE

With interest in TD-LTE growing, the Global TD-LTE Initiative (GTI) used the occasion of MWC 2013 to hold its seventh LTE TDD/FDD International Summit. The organization now has 51 operator members and 44 partners. Half a million TD-LTE base stations are expected to have been installed by 2014 according to the GTI, and eleven operators have launched commercial TD-LTE services.

The only discordant note in an otherwise upbeat summit was sounded by Sunil Mittal, Chairman of Bharti Airtel, who said that the operator’s TD-LTE rollout in the 2.3GHz band was experiencing coverage challenges. Mittal said that Bharti was working with suppliers including Qualcomm, ZTE, Huawei , NSN and others to improve the situation, but that the cell radius was nevertheless going to be “rather tight” and warned that the problems could mean that base station numbers for its TD-LTE commercial rollout, which began six months ago, could be in the hundreds of thousands, rather than the tens of thousands.

Mittal’s statement was not entirely surprising, however, given the Indian Government’s current deliberations over issuing spectrum in the 700MHz band, which could be used to provide coverage more cheaply and effectively than the 2.3GHz band outside dense urban areas.

Also at the Summit, China Mobile announced eight new TD-LTE devices, including own-branded products and models from LG, HTC, Huawei and ZTE, that it plans to introduce on its TD-LTE network later this year. The operator said it intends to purchase more than one million TDD devices this year.

China Mobile is currently trialling TD-LTE in 15 cities across China. The company’s chairman, Xi Guohua, announced that by year-end it will have more than 100 cities in China covered, making its network the largest TD-LTE network in the world.

The global drive behind TD-LTE is leading to a more unified ecosystem than that for LTE-FDD, says test company Anite, which has been working with China Mobile to develop device test cases. Anite said that whereas test cases for TD-LTE are applicable across any TD-LTE market, those for FDD are still dependent on individual operators’ network infrastructure and quality benchmarks.

VoLTE

With US operator Metro PCS having pioneered voice-over-LTE (VoLTE) services, others are expected to follow suit late in 2013 or early 2014. VoLTE was a key theme at MWC 2013, with Ericsson showing a claimed first converged TDD/FDD VoLTE call, which the company says shows it is possible to have a seamless service with these two variants. Ericsson expects to see a worldwide wave of VoLTE deployments along with strong growth in RCS, and was showing ecosystem growth around chipsets and devices.

Meanwhile, operators are waiting for Single Radio Voice Call Continuity (SRVCC) to become available so that IP voice call connection can be maintained as mobile users move from LTE to non-LTE coverage. According to test company Spirent, the next wave of devices will likely standardize on Qualcomm’s VoLTE client, although carriers would like to have more choice, the company believes.

IMS software provider Mavenir expects SRVCC to be available in devices by the year-end, with launches of VoLTE following in early 2014. The company is already adding rich communication suite (RCS) capability on top of Metro PCS’s VoLTE launch in the form of a downloadable client that supports RCS services such as video calling. Mavenir expects that when other US operators such as Verizon and AT&T launch VoLTE, they will actively market it as a new, improved voice service.

Radisys, which is partnering with Mavenir on a number of VoLTE solutions for operators by supplying Multimedia Resource Function (MRF) capability for real-time voice and video packet processing, says it too is seeing a lot of interest from operators in VoLTE and RCS. The company says it is already working with 10 operators in this area, including one in India.

LTE-A/B and 5G

As operator’s spectrum assets are increasingly squeezed, demand for LTE-Advanced is expected to grow, and Anite says devices supporting LTE-A will start hitting the market towards the end of this year. The company has been working with third parties to test support for Carrier Aggregation (one of the key features of LTE-A) and is working with device developers initially to combine 2 x 10MHz channels, moving to a combination of 2 x 20MHz. Anite says that the process of validating devices for CA will be a protracted one, however, with some aggregated bands being adjacent while others are widely dispersed.

Looking further ahead, Huawei was touting its LTE-B Fusion Net concept at MWC. The technology introduces a ‘boosting layer’ into the network to increase throughput, and supports a feature called multi-stream aggregation (MSA) for UMTS, LTE and Wi-Fi, which helps to improve cell edge performance and peak rates while managing the user’s data experience within hetnet environments. MSA is proposed for inclusion in 3GPP Release 12.

Others at the show had their sights set on 5G, and a seminar hosted by the ICT Knowledge Transfer Network (ICT KTN) speculated on what form the next generation of mobile technology might take.

Professor Rahim Tamazoli of the University of Surrey in the UK, said that 5G was not about speed but rather the viability of the mobile broadband case in the face of dwindling spectrum capacity, and he called for more research into capacity per area (area spectrum efficiency) as a measure of rising demand. As to the technology expected to be employed, Prof Tamazoli expected that 5G would be based on an entirely new air interface based on new orthogonal waveforms, rather than on OFDM.