PERSONAL COMMUNICATIONS VIA INTELSAT KU-BAND TRANSPONDERS

The concept of a fully meshed network of very small terminals is presented for personal communications over K(u)-band satellite transponders. In this concept, undesirable double-hop delays are avoided for voice communications between these terminals. The bandwidth and power resources of the transponder are efficiently shared by users in a simple demand-assigned manner via code-division multiple access (CDMA).1,2 Voice, data and facsimile are statistically multiplexed at each terminal. In order to minimize terminal costs, frequency-precorrected and level-preadjusted continuous wave (CW) tones are sent from the central network control station in each beam. The terminals in each down-link beam can use these pilots as references for antenna acquisition and tracking, as reliable frequency sources, and as indicators of signal fade for up-link power control (ULPC). The potential CDMA 'near-far' problem due to up-link fades is mitigated by using ULPC. Quasi-burst-mode transmission is employed to minimize the potential loss of clock and pseudorandom number code synchronization. When these terminals are used only to interconnect into the public switched telephony networks (PSTNs) through large, hub-like gateway stations, they can employ flat-plate antenna technology. The complete terminal can thereby be packaged into a briefcase so that it is easily transportable for personal use.