Multiple Antennas Key to Mobile Broadband
WiMax is already specified to support multiple antenna systems, and they're also being incorporated in specifications such as 3rd Generation Partnership Project (3GPP) ’s UTRAN LTE (Universal Terrestrial Radio Access Network Long Term Evolution, or Super 3G).
In addition, Ericsson AB (Nasdaq: ERIC) is even talking about supporting them in its HSPA (High Speed Packet Access) developments. (See Ericsson CEO Talks.)
“Multiple antenna systems have been around for many years, but their performance in the labs has tended to deteriorate markedly in the field” says the report’s author, Heavy Reading senior analyst Patrick Donegan. “But given the likely evolution in users’ expectations of mobile broadband services, operators will have little choice but to revisit them. They will have to work with vendors, ancillary suppliers, and local planning authorities to resolve the issues surrounding cost, instability, and environmental planning." (See DoCoMo Trials 4G.)
Among the different approaches, MIMO (Multiple Input Multiple Output) and AAS (Adaptive Antenna Systems) stand out as the two most popular with vendors, the report finds. In the case of CDMA 1X EV-DO and HSPA, they are being rolled out with conventional antenna systems supporting a theoretical maximum of 3.1 Mbit/s and 14.4 Mbit/s in the downlink respectively.
However as the 3GPP and 3rd Generation Partnership Project 2 (3GPP2) releases evolve over time, throughput rates of 100 Mbit/s in the downlink and 50 Mbit/s in the uplink are being targeted.
“There’s no near-term need for multiple antenna systems other than in the case of WiMax, which is initially being deployed for fixed applications”, says Donegan. “But over time, mobile operators deploying them will be able to achieve throughput rates potentially 50 percent greater, or more, than those that don’t."
As with many key technology developments, there's something of a new "Holy War" breaking out among mobile infrastructure vendors, with some aggressively pushing the benefits of one multiple antenna system approach versus another.
However, the report states that different approaches will inevitably be required to meet different operator needs. Moreover, some approaches will even go as far combining the benefits of MIMO and AAS in a single solution.
Ericsson seems to be unique among infrastructure vendors in aggressively pushing the use of MIMO techniques with HSPA. (See Ericsson Demos 28-Mbit/s HSPA.)
“HSPA is only now being rolled out on a large scale”, Donegan says. “As the market leader, Ericsson wants to be able to extend the life of HSPA as far as possible, just as it did with Enhanced Data rates for GSM Evolution (EDGE). With HSPA, multiple antenna systems are a part of Ericsson’s proposition."
Most other vendors seem to believe that multiple antenna systems are better suited to systems that employ OFDMA (Orthogonal Frequency Division Multiple Access) modulation such as WiMax, UTRAN LTE, and CDMA 1X EVDO Revision C. (See Moto Takes All Sides of Orthogon, Nortel Bolsters WiMax Position, Mobile WiMax Goes Mini, and Nortel Touts HSOPA.)
Nokia Corp. (NYSE: NOK), usually among the most aggressive with next-generation mobile infrastructure marketing (MAWNGMIM), seems to be among the least active in promoting the technology (LAPT), notes Donegan.
— The Staff, Light Reading