The world’s first live over-the-air test of ‘dual channel’ 3G HSPA+ on Telstra’s Next G network doubles download speeds to 22Mbps ‘under controlled conditions’.
Telstra has conducted its first live trial of ‘dual channel’ technology on its Next G network, ahead of the technology’s rollout later this year in “selected selected locations … in areas of high demand” – typically built-up areas where the demand for additional speed is greatest.
The test was conducted on from an active Next G base station rather than in the labs, in what Telstra’s Chief Operations Officer Michael Rocca describes as “a good signal environment under controlled conditions” in a post on the
Telstra Exchange blog.
Average download speed were around 22Mbps, which Rocca says is “approximately double those experienced under the same conditions at the same location with a standard BigPond Elite HSPA+ rated device”.
The trial used “an advanced pre-production model of a USB mobile broadband device that is dual channel-enabled.” (This is likely to be the stout blue dual-carrier dongle made by Sierra Wireless and demonstrated earlier this year when Telstra announced its dual-channel strategy at Barcelona’s Mobile World Congress earlier this year.)
A Telstra spokesman told APC that the rollout of dual channel is “expected to be concentrated in areas of high traffic demand in major capitals and regional centres.”
Few people will ever see the needle hit 22Mbps, of course, but Rocca maintains that “we should see approximately double existing HSPA+ customer download speeds” in those parts of the Next G network which are upgraded to dual-channel.
This is expected to translate into a peak of 8-10Mbps in real-world rates, based on solid 4MBps results in pockets of Next G where the cells run at a maximum 21Mbps.
Dual channel ramps this up to 42Mbps by doing pretty much it says on the tin – using two HSPA+ data channels to double network speed compared to a single channel.
At the same time, assigning a second data channel to any user means one less channel available for other Next G customers. This could lead to congestion issues and problems with reduced speed among single-channel customers if the capacity of each upgraded base station isn’t carefully managed and provisioned to cope with demand.
Hence, Telstra is also upgrading its network with ‘high-speed backhaul’ fibre-optic links between Next G base stations and Telstra’s Next IP network core.
Telstra says it has already upgraded “a substantial proportion” of the fibre-optic links with Ethernet backhaul “to provide 100Mbps of capacity between base stations and the rest of the network – more than enough to support HSPA+ speeds. This capacity boost removes potential bottlenecks from the network and helps to ensure services are fast, responsive and reliable.”
“More than 80 percent of the Australian population is served by Telstra base stations with high bandwidth backhaul”, the spokesman said. “Of these, more than 75 percent use optical-fibre enabled Ethernet connections, while the rest are supported by at least 8Mbps backhaul capacity using traditional E1 technology.”