Expect between half to one Mbps in busy cells
UMTS cell sites equipped with HSDPA technology will probably offer users average data rates of between 500kbps and 1.5Mbps when they are working at full capacity, the results of trials carried out by Motorola suggest.
Motorola has been conducting HSPDA (High Speed Downlink Packet Access) trials with five European operators, simulating a variety of different network conditions, including that of a cell working at peak capacity. HSPDA is labeled by the 3GPP standard as having a peak of 3.6Mbps on the downlink (and 14.4Mbps with the most powerful modulation), but Raghu Rau, corporate vice president for marketing for Motorola's networks business, says that in reality the throughput will be tempered by the amount of users in a cell, and the extent of their use.
“Motorola estimates that the average user throughputs will be approximately between 500kbps and 1.5Mbps during the download. Overall HSDPA will appear to the user between 3 and 10 times faster than UMTS. This differential will increase as the cell size gets smaller," Rau said.
Motorola did clock a speed of 2.9Mbps in one of its trials, at the edge of a cell using a single HSDPA test device.
The trials were designed help the mobile operators concerned build optimised HSDPA-enabled networks. The results will also help the operators design networks that offer highly reliable 3G connectivity, access and competent service delivery considering a variety of traffic levels, service demand, device and location.
Motorola set up a menu of test options for the participating operators to choose from, to mimic the individual operating conditions of each network, with different access options to measure performance, compatibility and interoperability.
During the trials, services ranging from e-mail, video streaming, music downloads and web browsing are being tested for speed, capacity and data quality from
normal to high-traffic conditions.
HSPDA offers enhanced data rates on the downlink by adding a new downlink channel that is shared by users. Complex algorithms dynamically allocate bandwidth in the shared channel, which is managed by the existing Node B UMTS base station.