Sprint's Backhaul Bottleneck
Sprint's backhaul problems are said to be a matter of lack of bandwidth to the WiMax cellsites, which are expected to pump in and out several megabits per second at launch, providing high-speed broadband links to 802.16e cards and other devices. Sprint CTO Barry West confirmed to Unstrung on Tuesday night that backhaul was "an issue." (See Sprint Quiet on WiMax Launch Date.)
The operator has been using T1 arrays but wants to rent more fiber and use Local Multipoint Distribution System (LMDS) microwave links to provide 20 Mbit/s or so of backend muscle for the WiMax sites, according to a vendor at the show.
Wireless network throughput is only as good as the connection to the wired network, as many home users have found when plugging new 100 Mbit/s-plus pre-802.11n wireless LAN routers into their DSL. The WiFi can be slowed by its weakest link. The same holds true for larger wireless networks.
Sprint has been trying to move away from using T1 lines for backhaul for some time now. It said in 2006 that it was searching for alternatives to its near-ubiquitous T1 links. The problem for the operator will likely be that while T1 is relatively cheap and easy, fiber is more costly, something it can ill-afford at the moment. (See How Is T1 Like a Pizza? and Sprint to Cut 4,000 Jobs.)
The word at the show, however, is that this is a temporary blip and that Sprint is expected to have markets up and running in the fall, if not earlier. Sprint has steadfastly refused to name a new date for its commercial Xohm launch and didn't return calls and emails for comment on a possible autumn launch.
— Dan Jones, Site Editor, Unstrung