Methods and systems for tandem IWF interconnectivity

Abstract

A unique byte is used to bookend commands and data for the purpose of allowing inband signalling and command communication between the IWF and the BSC portions of a mobile communication system having DS0 maximum data rate transfer capability per data channel. The receipt of two consecutive ones of the unique bytes indicates that the next 2 bytes will be a command. The receipt of 3 consecutive ones of the unique bytes indicates the next byte will be data. This inband signalling and data transfer allows the IWF functionality to be remote from the main switch used by a given BSC. The CDMA system uses the inband signals to pass a plurality of data packets in parallel on DS0 capacity channel links through the MTX in a half-duplex burst whenever a data buffer within the IWF or a connected high data transfer rate mobile station is filled to a given level. This burst process may operate on a time multiplex basis with low speed data transfers using the same DS0 links to communicate with the IWF. To simplify the design of the burst process mechanism as concerns the bit robbing occurring in the least significant bit position of each DS0 channel every 6th frame on DS1 communication lines linking the BSC and the MTX, only the 7 most significant bit positions of a data byte are used in the data transmitted between a IWF entity and the SBS portion of a mobile network.

What is claimed is:  
     
         1 . Mobile station communication apparatus, comprising: 
 a plurality of mobile switching centers; and    interworking function means tandemly connected through a mobile switching center to at least one other of said plurality of mobile switching centers.    
     
     
         2 . Mobile station communication apparatus, comprising: 
 a plurality of interconnected mobile switching centers; and    interworking function means connected to said plurality of mobile switching centers for receiving data calls therefrom.    
     
     
         3 . Selector bank subsystem apparatus in a mobile station communication system, comprising: 
 a first plurality p of first service option element means;    a second corresponding plurality p of digital signal processor means;    burst service option element means for processing a plurality M of serial channels of data between a given service option element means and a M plurality of said digital signal processor means where each of said digital signal processor means processes one of said M channels, said plurality M being no greater than p.    
     
     
         4 . A cellular communication system, comprising: 
 MTX means;    BTS means;    BSC means, interconnected between said MTX and said BTS means;    IWF means    first means within said BTS means for combining data, received substantially simultaneously on a plurality of data channels from a mobile station, to form a serial set of data packets for forwarding to said BSC means; and    second means within said BSC means for forwarding data packets, serially received from said BTS means, in parallel on a plurality of data channels through said MTX means to said IWF means.    
     
     
         5 . Apparatus as claimed in    claim 4    wherein said second means comprises a burst SOE interconnected between a plurality of SOEs and a plurality of DSPs.  
     
     
         6 . The method of accomplishing the forwarding of incoming data packets through a mobile switching center at higher than the maximum data rate of a single DS0 data channel comprising, the steps of: 
 assigning a given number of DS0 data channels in response to a caller specified desired maximum data rate; and    passing a plurality of data packets in a burst from input means to output means in response to a received burst request where the data packets on one of said input and output means is in serial format and the other comprises a parallel distribution of data packets among said given number of DS0 data channels assigned.    
     
     
         7 . The method of    claim 6    wherein the burst of data packets is supplied through a single entity in a half duplex mode whereby said single entity can continue to service data channels in the opposite half duplex mode.  
     
     
         8 . Apparatus for accomplishing the forwarding of incoming data through a mobile switching center at higher than the maximum data rate of a single data channel, comprising: 
 means for assigning a given number of data channels in response to a caller specified desired maximum data rate; and    means for passing data packets in a burst between a plurality of parallel channels and a serial channel, that is relatively high speed as compared to said parallel channels, in response to a received burst request.    
     
     
         9 . Apparatus for passing data between IWF and SBS entities at greater than the data transfer rate of a given interconnecting data channel, comprising: 
 high speed serial data transfer means comprising a part of said SBS;    a plurality of low speed, as compared to said high speed means, means interconnecting said IWF and said SBS;    burst means interconnecting said high speed means and said plurality of low speed means;    means for normally transferring data between said high speed means and said IWF via said burst means and a given one of said plurality of low speed means;    means for, in response to a request message, providing a burst of a predetermined number of data bytes using at least one further channel of said plurality of low speed means to transfer data in addition to the low speed means normally used for transferring data; and    means for dropping the use of the further channel when the predetermined number of data bytes has been transferred.    
     
     
         10 . The method of transferring data comprising the steps of: 
 normally using a given low speed data channel interconnecting two high speed data channel means until there is a data buildup at a data input end of said low speed data channel;    transferring data in parallel on said given low speed data channel as well as on a further low speed data channel in a burst for a predetermined number of data bytes; and    returning said further low speed data channel to its previous operational state when the data burst is completed.    
     
     
         11 . The method of    claim 10    where the low speed data channels are full duplex and wherein the data burst transfer operates in a first half duplex mode of two half duplex modes comprising the additional step of: 
 transmitting data in the other half duplex mode between the entities engaged in the previous operational state of said further low speed data channel during the burst of data occurring in the first half duplex mode.  
 
     
     
         12 . Apparatus for transferring data, comprising: 
 first means for normally transferring data on a given low speed data channel interconnecting two relatively higher speed data channel means until there is a data buildup at a data input end of said given low speed data channel;    second means for altering the normal transferring of data whereby it is additionally transferred in parallel on a further low speed data channel in a burst for a predetermined number of data bytes; and    third means for returning said further low speed data channel to its previous operational state when the data burst is completed.