Patent EA-000791-B1 (EA)
Title: Distributed circuit switched radiocommunications network
Inventor: CHANDLERS STEPHEN ANTHONY GERA
IPC: H04B7/15
Filed: 1996-09-27
Abstract: 1. A transmitting and receiving station for a telecommunication network in which a plurality of such stations are to be provided at randomly distributed locations and in which switching circuitry is provided within the stations themselves for routing of calls between stations in the network utilizing other stations in the network for relaying of such calls where necessary comprising the call interruption means (16) which is transmitted by a station (6) for receiving a new call to be received from the further station and comprising: (a) call monitoring means for receiving, during intervals of times between the relaying of speech or data signals within the existing call, an interrupting signal indicating a call request to the station from the further station; and (b) call accept means for interrupting the relaying of the existing call by the station in response to the interrupting signal to enable the new call to be received from the further station. 2. A station according to claim 1, wherein the call interruption means (16) incorporates re-routing means which, in response to receipt of the interrupting signal (34), selects an alternative route for relaying the existing call and, in the event of an alternative route being available, re-routes the existing call to enable the new call to be received from the further station. 3. A station according to claim 1 or 2, wherein the call interruption means (16) includes null transmitting means for transmitting null packets (35) indicative of gaps in the speech or data signals being transmitted within the existing call, the call monitoring means (30) being adapted to receive said interrupting signal (34) during transmission of said null packets (35). 4. A station according to claim 3, wherein the call monitoring means (30) is adapted to receive said interrupting signal (34) only after transmission of a sequence of null packets (35) has ceased. 5. A mobile transmitting and receiving station for use in for a telecommunication network in which a plurality of such stations are to be provided at randomly distributed locations and in which switching circuitry is provided within the stations themselves for routing of calls between stations in the network utilizing other stations in the network for relaying of such calls where necessary, wherein the mobile station comprises: a) registration means for transmitting registration signals to a fixed base transmitting and receiving station associated with the mobile stationutiising other fixed stations in the network for relaying of the registration signals where necessary such that the base station receives an indication of the approximate position of the mobile station from the location of the first fixed station used in relaying the registration signals; and (b) call reception means for receiving a call from a further station in the network relayed by way of the base station and routed towards the mobile station by the base station on the basis of the approximate position of the mobile station indicated by the registration signals, and for initiating routing of the call back to the further station following acceptance of the call. 6. A transmitting and receiving station for a telecommunication network comprising signalling means (55) for transmitting and receiving signals on the same frequency, transmitting means (50, 51, 52, 53) for transmitting signals by way of the signalling means (55), receiving means (56) for receiving signals by way of the signalling means (55), and switchingmeans (54) for switching the signalling means (55) between the transmitting means (50, 51, 52, 53) and the receiving means (56) in response to a control signal, wherein the transmitting means (50, 52, 52, 53) incorporates a frequency source (51) for supplying a frequency signal, bistable circuit means (50) for producing, by frequency division of the frequency signal, a carrier frequency for the signals to be transmitted, and inhibit means for turning off the bistable circuit means (50) to inhibit the carrier frequency in response to the control signal. 7. A digital transmitter for transmitting digitally modulated signals in short bursts, comprising symbol waveform generating means for generating for each symbol of the digital data to be transmitted a symbol waveform of limited duration (61, 62, 63 or 64), waveform convolution means (70) for combining a series of such symbol waveforms (61, 62, 63 or 64), such that each waveform is delayed with respect to and overlaps a previous waveform, so as to produce a combined waveform representative of a sequence of symbols of the digital data to be transmitted, and signal modulation means for linearly modulating a carrier waveform with said combined waveform so as to provide said modulated signals for transmission in short bursts without producing substantial spectral spreading, but without the use of separate ramp up and ramp down waveforms. 8. A digital receiver for receiving digitally modulated signals (80, 81, 82, 83, 84, 85, 86) comprising receiving means for receiving the digitally modulated signals and for producing therefrom symbol signals indicative of symbols within the transmitted digital data, sampling means(86, 87, 88, 89, 90, 91, 92) for sampling the symbol signals at sampling points determined by a clock signal in order to provide a received data output signal corresponding to the transmitted digital data and an error output signal, and sampling synchronisation means (93, 94, 95) for synchronising sampling of the symbol signals by the sampling means by adjusting the timing of the clock signal to minimise the error output signal.