Huawei Ups the HSPA+ Stakes
The demo took place at P&T/Wireless & Networks Comm China 2009 in Beijing and employed both multiple input and output antennas(MIMO) and channel-splitting multi-carrier radio modulation to reach the 56-Mbit/s peak rate. According to the company, all of Huawei's 116 or more HSPA customers can move to 56-Mbit/s HSPA+ networks via software upgrades alone. (See Huawei Preps Next Gen HSPA+.)
To increase the speed of HSPA (High-Speed Packet Access) from its top theoretical downlink of 14 Mbit/s, vendors have three techniques available to them: MIMO, multi-carrier, and QAM64. MIMO uses more than one pair of antennas -- typically 2-by-2 or 4-by-4 -- to increase data send and receive speeds. Multi-carrier modulation (MCM) is a technique that splits up the data being transmitting and sends it over a number of smaller channels (or "carriers") as a way to boost speed while cutting radio interference. QAM64 is a type of Quadrature amplitude modulation, also frequently used by cable vendors, that varies the amplitude and phase of a signal to increase the data capacity.
With its new system, Huawei is attempting to be the first vendor to launch a commercial solution that combines MIMO and multi-carrier techniques.
According to Dan Warren, director of technology at the GSM Association (GSMA) , MIMO can double speeds, and multi-carrier will increase speeds by the number of carriers being bonded, which in this case is two. These techniques combined allow the software upgrade to deliver 56 Mbit/s, far more than the peak rates offered by most commercial HSPA networks today.
QAM64 modulation techniques, meanwhile, typically multiply data speeds by about 1.5 times. QAM64 is considered to be the easiest HSPA speed boost to apply and has been used by many other infrastructure vendors. Huawei, however, has decided not to implement the technology on its HSPA+ upgrade yet.
Indeed, all the HSPA+ deployments, bar Telecom Italia Mobile SpA (Milan: TIM)'s in Italy, have been achieved with QAM64. Ericsson AB (Nasdaq: ERIC) is responsible for the TIM network and the Swedish vendor is working with Telstra Corp. Ltd. (ASX: TLS; NZK: TLS) in Australia on deploying MIMO to raise the operator's peak rates to 42 Mbit/s. Ericsson also demonstrated multi-carrier technology at the Mobile World Congress in February, proving its capability to deliver all three multiplier technologies. (See Ericsson Pumps Up HSPA.)
In an email response to Light Reading's questions on the exclusion of QAM64, Huawei says, "The biggest technical challenge for the 56 Mbit/s solution lies in the MIMO and duel cells technologies. The easy achievable technology like QAM64 is not considered this time" -- suggesting the addition of QAM64, which would take speeds to 84Mbit/s would be easy and therefore not long in coming.
As such, it could take operators close to the theoretical 100-Mbit/s peak rates offered by LTE, if not the other benefits such as latency improvements, and pit HSPA+ and LTE head to head. Of course, none of these technologies are likely to achieve maximum downlink speeds when actually deployed commercially.
According to Gabriel Brown, analyst at Light Reading's sister analyst group, Heavy Reading, any battle between LTE and HSPA+ is a "false argument," as both technologies will be deployed. He says, "Operators will go to LTE when they get fresh spectrum and use HSPA+ in 3G spectrum." (See 3G vs LTE: No Contest.)
Brown is also convinced that HSPA+ will continue to be developed as operators look to maximize their investments, suggesting that "Operators could deploy LTE and keep upgrading HSPA in the same way as they have upgraded GSM to EDGE even though they have 3G."
Warren agrees and says this strategy that has been made much easier since the development of flexi or multi-technology base stations. He says, "Flexi base stations are great for operators because they can make the switch from HSPA to LTE at any point they choose."
Alcatel-Lucent (NYSE: ALU), Ericsson, Nokia Networks and ZTE, in addition to Huawei all have flexi products but not all HSPA deployments use such flexi base stations. This means that some operators, particularly those such as AT&T Inc. (NYSE: T) that went to HSPA early before flexi BTS were introduced, will face a starker decision to shift to LTE.
As a result there are three operator groups emerging, according to Warren. The first is made up of operators that bought very recently and have flexis and are in his words "all set."
The second group of operators haven't invested in infrastructure for a long time and need to do something in the near future. However, they have carte blanche as the return on investment for their last investments have been fulfilled.
And finally, the third group is made up of those in the middle, which have kit that upgrades through some or all of HSPA iterations, but which bought it recently and so need to get more from their investments.
Huawei confirms that it has 15 HSPA+ customers worldwide, including Singapore's StarHub , Hong Kong's PCCW Ltd. (NYSE: PCW; Hong Kong: 0008) and Japan's E-mobile and in Japan, all three of these groups are represented. (See Japan's EMobile Pumps Up Its HSPA+ and DoCoMo Shells Out on LTE.)
E-Mobile has deployed HSPA+ recently, and SoftBank Mobile Corp. went early to HSPA and is keen to maximize the return on its HSPA assets, while NTT DoCoMo Inc. (NYSE: DCM) has reaped its payback on its 3G infrastructure and is pushing fast toward LTE. Perhaps the deciding factor, as these operators play out their technologies in a single market, will be the devices.
There is no obvious front runner with devices as the HSPA+ multipliers require new devices just as LTE does. What is more, the support of dual antennas for MIMO in both HSPA and LTE is proving far from straightforward, especially at lower frequencies where the spatial separation, otherwise known as the distance needed between the antennas to avoid interference, is much higher.
— Catherine Haslam, Asia Editor, Light Reading