by Andrew J. Shepherd
Sprint 4G Rollout Updates
Friday, March 9, 2012 - 1:15 PM MST
Sprint may soon be gaining some clarity regarding its Network Vision plans to deploy CDMA1X Advanced to replace Nextel iDEN in its rebanded SMR 800 MHz spectrum. The FCC today announced a proposed rulemaking that would explicitly allow SMR 800 MHz licensees (e.g. Sprint, SouthernLINC, and a few others) to utilize greater than 25 kHz channel spacing.
Currently, Part 90 SMR 800 MHz rules and regulations could be interpreted to prohibit channel spacing exceeding 25 kHz, effectively disallowing any airlink other than iDEN, which is designed to operate in 25 kHz channelization. Meanwhile, Sprint has petitioned that Part 90 does not automatically bar larger channel bandwidths in contiguous channel blocks and that it has enacted improved filtering techniques to satisfy out of band emissions concerns due to wideband operations.
To reconcile the current rules and regulations with Sprint's contentions, the proposed rulemaking would amend Part 90 as follows:
More simply put, Sprint would be able to use its lower band SMR 800 MHz spectrum below 821 MHz x 866 MHz right away to deploy CDMA1X and/or LTE. Then, after all public safety relocation in a region has been completed, Sprint could utilize its upper band SMR 800 MHz spectrum 821-824 MHz x 866-869 MHz for further wideband operations.
The proposed rulemaking aligns with and helps to explain Sprint Network Vision 3G plans that S4GRU has obtained. Those plans indicate that Sprint intends to deploy at least one CDMA1X Advanced band class 10 carrier channel centered at channel 476 (817.9 MHz x 862.9 MHz) and/or channel 526 (819.15 MHz x 864.15 MHz). This would place one or both CDMA1X carrier(s) within the lower band 817-820 MHz x 862-865 MHz spectrum and leave >1 MHz guard bands between it and 821-824 MHz x 866-869 MHz spectrum, in which public safety reconfiguration is still ongoing in some regions.
To illustrate how Sprint proposes to roll out CDMA1X 800 at the lower end of its SMR 800 MHz spectrum allotment, see our band plan and channel assignment graphic:
Sources: FCC, Sprint, author's graphic