Editing DirectBand (section)

== How it works ==
DirectBand used the 67.65&nbsp;kHz [[subcarrier]] leased by Microsoft from commercial radio broadcasters. This subcarrier delivers about 12&nbsp;kbit/s (net after [[Error-correcting code|ECC]]) of data per tower, for over 100&nbsp;MB per day per city. Data included traffic, sports, weather, stocks, news, movie times, calendar appointments, and local time.

=== Not like RDS ===
DirectBand did not use the RDS ([[Radio Data System]]) subcarrier. RDS is a different system and has much lower data rate (~730&nbsp;bit/s after ECC, including framing). Its much narrower subcarrier is primarily used for radio station information and traffic. DirectBand and RDS can co-exist on the same FM station.

=== Forward acting error correction ===
Since many DirectBand uses were mobile, and there was no opportunity to request retransmission of a broadcast signal, DirectBand utilized an advanced error-correction strategy that allowed for reconstruction of messages even when sizable portions of the message were lost due to buildings, tunnels or other obstructions of the FM signal. Error correction was 1/2 rate interleaved [[Trellis modulation|trellis]] with time diversity, soft-decision decode. The DirectBand data rate was in excess of 12&nbsp;kbit/s after ECC.

=== Push network ===
DirectBand was a push network{{snd}} new content was delivered every two minutes. Users pre-selected the virtual channels that they were interested in.