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A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access

A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDM channels. The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FSC) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC). The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system.

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A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access

A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDM channels. The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FSC) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC). The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system. 00, Budge et al.; US-5793425, 19980800, Balakrishnan; US-5802106, 19980900, Packer; US-5815503, 19980900, Li; US-5854658, 19981200, Uz et al.; US-5861919, 19990100, Perkins et al.; US-5862140, 19990100, Shen et al.; US-5877812, 19990300, Krause et al.; US-5923655, 19990700, Veschi et al.; US-5928331, 19990700, Bushmitch, 709/231; US-5956088, 19990900, Shen et al.; US-5966120, 19991000, Arazi et al.; US-6005620, 19991200, Yang et al.; US-6011590, 20000100, Saukkonen; US-6023456, 20000200, Chapman et al.; US-6389068, 20020500, Smith et al., 375/225 ltiplex data, and distributing the multiplex data to the plurality of terminal apparatuses. ta packets to the application servers, each of said de-fragmenters including: means for reassembling incoming data packets out of incoming packet fragments; andmeans for identifying a valid application server from the plurality of application servers for receiving the reassembled incoming data packets;a plurality of forwarding processes, each of the forwarding processes being associated with one of the plurality of network terminations, each of said forwarding processes including means for identifying a single de-fragmenter from the plurality of de-fragmenters to receive all of the incoming data packets and packet fragments having a common source address;a plurality of interprocess communication (IPC) links between each of the forwarding processes and each of the fragmenter/de-fragmenters; anda plurality of IPC links between each of the fragmenter/de-fragmenters and each of the application servers.13. A Framework for providing a fault-tolerant and scalable interface that receives outgoing data packets from a plurality of application servers and passes outgoing data packets and packet fragments to a packet data network (PDN), said Framework comprising: a plurality of forwarding processes; a plurality of fragmenters that receive outgoing data packets from the application servers, each of said fragmenters including: means for fragmenting outgoing data packets into outgoing packet fragments; andmeans for identifying a forwarding process from the plurality of forwarding processes for forwarding outgoing data packets and packet fragments to a network termination; a plurality of network terminations that send outgoing data packets and packet fragments to the PDN, each of the network terminations being associated with one of the plurality of forwarding processes; a plurality of interprocess communication (IPC) links between each of the fragmenters and each of the application servers; and a plurality of IPC links between each of the fragmenters and each of the forwarding processes. 14. A fault-tolerant and scalable method of interfacing a plurality of application servers with a packet data network (PDN), said method comprising the steps of: receiving in a plurality of network terminations, incoming data packets and packet fragments from the PDN; associating each of the network terminations with one of a plurality of forwarding process; connecting each of the forwarding processes to a plurality of fragmenter/de-fragmenters; selecting by each forwarding process, a single fragmenter/de-fragmenter to receive all of the incoming data packets and packet fragments having a common source address; sending the incoming data packets and packet fragments having a common source address to the selected fragmenter/de-fragmenter; reassembling by the selected fragmenter/de-fragmenter, incoming data packets out of the incoming packet fragments received from the forwarding processes; connecting each of the fragmenter/de-fragmenters to the plurality of application servers; identifying by the selected fragmenter/de-fragmenter, a valid application server from the plurality of application servers for receiving the reassembled incoming data packets; and sending the reassembled incoming data packets from the selected fragmenter/de-fragmenter to the valid application server. 15. The fault-tolerant and scalable method of claim 14 further comprising the steps of: selecting by the valid application server, a fragmenter/de-fragmenter from the plurality of fragmenter/de-fragmenters; sending outgoing data packets from the valid application server to the selected fragmenter/de-fragmenter; identifying by the selected fragmenter/de-fragmenter, a single forwarding process from the plurality of forwarding processes; sending the outgoing data packets from the selected fragmenter/de-fragmenter to the identified forwarding process; associating by the identified forwarding process, the outgoing data packets with a network