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Mobile World Congress: LTE trials mount up but mood is still cautious
|27 февраля 2010
In the home of the 3GPP carriers at Mobile World Congress, there was less hype about LTE than many had expected, though there was plenty of talk of trials and pre-commercial products. More important were issues of extending the life of 3G networks with successive HSPA upgrades, and of migrating ’smoothly’ to LTE with unified cores and overlay strategies.
Obstacles to rapid LTE progress were discussed as much as the promise of the new technology, with spectrum fragmentation, device timelines and the perennial voice issue all in the limelight.
Meanwhile, the WiMAX community was stressing its headstart, with a strong line-up of operators using the technology for real world and advanced business models. And as it looked to the new standard, WiMAX2, its supporters were showing increased maturity in addressing a wide range of business cases, some of them heavily geared to coexistence with cellular networks - 2G in emerging markets, 3G for offload and rapid broadband migration, even LTE for some operators with certain spectrum or market requirements.
First, the good news for LTE. It really is achieving a unified operator community worldwide, mending the old CDMA/GSM divide for good. This was highlighted by the decision of three CDMA majors - China Telecom, KDDI and Verizon Wireless - to join the GSM Association, which also represents carriers using W-CDMA/HSPA and now LTE. And in the most symbolic move of all, Qualcomm joined the GSMA as an associate member - no surprise given its likely market lead in LTE device silicon and its huge participation in HSPA, but nonetheless, offering a final laying down of arms in the mobile war.
Then, the bad news. Unity is not what drives the mobile industry to greater lengths and LTE is already facing wars of its own. One is with ‘the other 4G standard’, WiMAX - boasting over 550 commercial deployments and with its next generation iteration, 802.16m or WiMAX2, due to be finalized this year, keeping its headstart over LTE-Advanced (these two standards hope to achieve ‘true 4G’ capabilities like 100Mbps mobile download rates, and both are submitted as candidates for the ITU’s IMT-Advanced set of official 4G platforms). What is really important is how much ground WiMAX will take from LTE before the latter becomes commercially mainstream, which most - despite a host of first stage deployments - think will be 2013. WiMAX, for its part, hit that point last year, after several years of work on certification, device ecosystem and service models, all of which still lie ahead of LTE.
The WiMAX community was very clear at Barcelona - it will steal ground in the mobile world on three main fronts. One, by powering alternative operators that are pursuing non-traditional business models such as machine-to-machine or advanced wholesaling. Two, by acting as a data offload partner for 3G carriers whose networks are under strain, at least until they have significant LTE capacity built out. And three, by providing a quick route to data services for 2G-only carriers in developing markets.
It can afford, for a short while at least, the smugness of being the ‘real’ technology. It has 555 deployments, though many of these are using fixed WiMAX and/or are very small. However, 95 are with mobile operators, many using WiMAX as a data overlay for 2G in markets where 3G is scarcely available. This contrast with 74 cellcos that have committed to trials or deployments of LTE, and two commercial operators, though the figure will clearly expand substantially this year.
But MWC was not the LTE-fest some had expected. The overall tone was one of caution about promising too much too soon, with carriers stressing ‘realistic’ timescales and efforts to eke the most out of 3G first. Even Qualcomm, which is likely to be the first tier one chipmaker to have LTE device silicon, was notably cautious about timelines and the time it will take to achieve a mass market. And many of the vendors were mainly focusing on HSPA+ roadmaps and demonstrations.
Even so, the LTE trials and commitments mount up. This is a summary of the main ones that surfaced during the Barcelona festivities.
SFR, Vodafone’s joint venture in France, has turned to home supplier Alcatel-Lucent plus Nokia Siemens for 3G/3G expansion and for early LTE trials, with a view to deploying the new system as an overlay with a converged core (a popular approach with 3G carriers with sufficient spectrum, as it reduces first stage cost). The trials will focus on performance and on multimedia applications. NSN, which has been overshadowed by Ericsson and Huawei in European LTE so far, has a strong platform for overlay strategies, the Flex Multiradio base stations. SFR is looking to use this to reuse 900MHz GSM spectrum for rural 3G, and to simplify its network overall, and Flexi could also support migration to LTE. NSN will also implement, operate and maintain SFR’s mobile packet core and associated IP network. Meanwhile, ALU will provide its own multi-platform RAN, the new MC-TRX, which is heavily focused on refarming.
Across the Atlantic, cableco Cox Communications says it has completed initial LTE tests in AWS and 700MHz spectrum in Phoenix, Arizona and San Diego, California. The trials achieved peak download speeds around 25Mbps, but Cox’ VP of wireless services, Stephen Bye, stressed the wireless system would be “complementary” to the cable network, and that LTE would never handle the traffic loads that wired internet users generate. Cox used equipment from Huwaei and ALU for its trial. It is one of the only major cablecos that is pursuing its own 4G build-out rather than participating in the Clearwire WiMAX based initiative, and also has an MVNO deal with Sprint. Its peak speeds were achieved using 2×2 MIMO in a 2×5MHz channel in AWS, but were only seen close to the cell site and with a single user - at the edge, speeds were about 10Mbps and this would, of course, reduce with multiple users.
Motorola has been counting on its TDD experience in WiMAX to give it a headstart in the TDD flavor of LTE, and has - with ALU - got the deal to deploy China Mobile’s first TD-LTE network, for the Shanghai Expo this year. But the firm has made some FD-LTE inroads too, notably with KDDI in Japan and now Zain Saudi Arabia. Zain’s roll-out will start in the second half of this year, in capital Riyadh. Motorola will provide RAN and evolved packet core infrastructure, 4G devices, plus network optimization and integration services. The network will operate in the 2.6GHz band, overlaying Zain’s 3G infrastructure. In China, ALU said it had achieved peak download rates of more than 80Mbps on the China Mobile system, using a single 20MHz band.
Saudi Arabia is becoming something of a hotbed of 4G, after lagging in 3G - it has several WiMAX services and now two LTE trials. As well as Zain, incumbent Saudi Telecom Company (STC) has awarded Ericsson an LTE contract.
Alcatel-Lucent has been selected by MTS Ukraine to conduct an LTE trial, which will begin in the second half of 2010. Andrei Dubovskov, head of the Russian-owned cellco, said: ‘The launch of the trial LTE solution will enable us to assess the benefits of 4G technology not just in theory but through real practical experience.’ ALU will provide LTE base stations, the evolved packet core, IP service routing network elements as well as operation, administration and maintenance (OAM) systems, project management, planning, installation, integration and commissioning, and testing.
MobileOne of Singapore has worked with Nokia Siemens to achieve transmission speeds of 100Mbps on a data call, on its trial LTE network. The carrier commented: “Our network modernization contract with Nokia Siemens represents the first steps in our evolution towards LTE, and this trial helps pave the way to faster and better quality mobile broadband services in the future.’
The flagship LTE operator, Verizon Wireless, said it was on track with its LTE plan. CTO Dick Lynch said its network was now in fourth-phase testing and due in 25-30 US cities this year, potentially reaching 100m people. Verizon expects to deliver 5-12Mbps downstream and 2-5Mbps upstream in 700MHz spectrum.
ZTE has been overshadowed by Huawei’s list of LTE trials, but had one of its own to announce just in time for Barcelona, at Hungarian carrier Pannon. Pannon is part of the Telenor Group, which has been moving very aggressively on LTE in its Norwegian home, and also putting cats among pigeons by working with Huawei rather than the regional giant Ericsson. It claims it is saving up to 50% by choosing the Chinese vendor over its incumbents Ericsson and NSN. Now its Hungarian unit has picked ZTE for its live network trial, which if successful, could lead to a commercial deal around midyear. ZTE will provide radio and core infrastructure as well as user terminals.
This partial list shows that LTE will be, for some time, very much a developed market play. Here, the operators must wrestle with pricing models and business cases, and also wait for a device ecosystem to evolve. Ironically, those issues are less important in developing economies, where WiMAX will aim to keep its lead, and to offer a 2G/4G proposition to GSM or CDMA 1X carriers.
Источник: 4G Trends