| 摘要 |
All existing two-way mobile communications technologies are narrow-band, fixed bandwidth and symmetrical, that is, out-bound and in-bound channel are of size equal. The invention is asymmetrical, the out-bound transmission to the mobile user is much higher in bandwidth than the in-bound channel. Further the out-bound bandwidth is variable; it can be tailored to meet service requirements. The invention comprises a plurality of digital data broadcasting transmitter systems (12) which operate in the frequency bands 2,310-2,320 and 2,345-2,360 MHz (S-band). The invention also includes user terminals (14) which are capable of receiving a plurality of S-band channels, and capable of transmitting in one or more traditional wireless communications bands. |
