Channel allocation method and apparatus

Abstract

In a satellite communications network, local pools of available carriers are assigned to each ground earth station GES by a network channel management station NCMS, which stores a pool of unallocated carriers. If the number of unused carriers in a local pool falls below a predetermined level, additional carriers are allocated from a regional pool in the network channel management station NCMS. If the number of carriers in a local pool exceeds a predetermined level, the excess carriers are released to the regional pool so that they can be allocated to local pools in other ground earth stations GES.

1 . Apparatus for selecting a channel for wireless communications, comprising: 
 storage means arranged to store data representing available communications channels,    selecting means for selecting one of the available communications channels for a communication,    requesting means for sending a request signal to a remote station in response to the number of available communications channels falling below a predetermined low level of at least one;    receiving means for receiving from the remote station an allocation signal representing a number of additional communications channels, the number being a non-negative integer, and    modifying means for modifying said data so as to additionally include any of said additional communications channels as ones of said available communications channels.    
     
     
         2 . Apparatus as claimed in    claim 1   , including adjusting means for adjusting the value of the low level.  
     
     
         3 . Apparatus as claimed in    claim 1    or    claim 2   , wherein the modifying means is operable to modify said data so as to remove one or more channels from the available communications channels, further comprising: 
 sending means for sending to the remote station a channel release signal representing the one or more removed channels.  
 
     
     
         4 . Apparatus as claimed in    claim 3   , wherein the modifying means is responsive to the number of available communications channels rising above a predetermined high level.  
     
     
         5 . Apparatus as claimed in    claim 4   , wherein the adjusting means is operable to adjust the value of the high level.  
     
     
         6 . Apparatus as claimed in    claim 2    or    claim 5   , wherein the adjusting means is responsive to a level control signal from the remote station.  
     
     
         7 . Apparatus as claimed in any preceding claim, including reporting means for sending to the remote station said data representing available communications channels.  
     
     
         8 . Apparatus as claimed in any preceding claim, including replacing means for replacing said data with backup data representing backup available communications channels.  
     
     
         9 . Apparatus as claimed in any preceding claim, including communication means for performing communication via the selected channel.  
     
     
         10 . A method of selecting channels for wireless communications, comprising storing data representing available channels, selecting one of the available channels or a communication, sending a request signal to a remote station in response to the number of available communications channels falling below a predetermined low level of at least one, receiving in response thereto an allocation signal representing a number of additional communications channels, and modifying said data so as additionally to represent said additional communications channels.  
     
     
         11 . Apparatus for controlling the allocation of channels to each of a plurality of wireless communications stations each of which includes local storage means for storing data representing communications channels available to that communications station and selecting means for selecting one of the available communications channels for communication by that communications station, the apparatus comprising: 
 receiving means for receiving from any one of said communications stations a request signal,    allocating means for allocating a number of additional communications channels for that communications station from which the request signal was received,    sending means for sending to that communications station an allocation signal representing the additional communications channels, and    level control means for sending a level control signal to any one of said communications stations, the level control signal being arranged to control the number of available communications channels at the respective communications station.    
     
     
         12 . Apparatus as claimed in    claim 11   , wherein the receiving means is arranged to receive a channel release signal from any one of said communications stations indicating a number of channels no longer available to that communications station, such that said released channels are made available for subsequent allocation by the allocating means.  
     
     
         13 . Apparatus as claimed in    claim 11    or    12   , including reserve storage means for storing data representing reserve channels not currently available to any of the communications stations, the allocating means being arranged to allocate the additional communications channels from said reserve channels.  
     
     
         14 . Apparatus as claimed in    claim 13   , including status receiving means for receiving status data from the communications stations, and deriving means for deriving the data representing the reserve channels from said status data.  
     
     
         15 . Apparatus as claimed in any one of    claims 11    to    14   , wherein the level control means is arranged to determine said level control signal in accordance with current and/or predicted demand for communications at the respective communications station.  
     
     
         16 . Apparatus as claimed in any one of    claims 11    to    15   , wherein the level control means is responsive to report data received from the communications stations indicating communications activity thereat.  
     
     
         17 . Apparatus as claimed in any one of    claims 11    to    15   , wherein the level control means is arranged to determine the level control signal such that all the available channels collectively satisfy a predetermined criterion.  
     
     
         18 . A method of controlling the allocation of channels to each of a plurality of wireless communication stations each of which is able to store data representing communications channels available to that communications station and to select one of the available communications channels for communication, the method comprising receiving from one of said communications stations a request signal, selecting a number of additional communications channels for that communications station, sending an allocation signal representing the additional communications channels to that communications station, and sending a level control signal to one or more of aid communications stations so as to control the number of available communications channels at the respective one or more communications stations.  
     
     
         19 . Apparatus as claimed in any one of    claims 1    to    9    or    claims 11    to    17   , wherein the channels are satellite communications channels.  
     
     
         20 . Apparatus as claimed in any one of    claims 1    to    9    or    claims 11    to    17   , wherein the channels are terrestrial cellular communications channels.  
     
     
         21 . A communications station including apparatus as claimed in any one of    claims 1    to    9   , or    claim 19    or    20    when dependent thereon.  
     
     
         22 . A network control station including apparatus as claimed in any one of    claims 11    to    17   , or    claim 19    or    20    when dependent thereon.  
     
     
         23 . A satellite including apparatus as claimed in    claim 19   .