Network Managed Channel Change In Digital Networks

Abstract

There are provided a circuit and corresponding method for enabling a channel change in a digital network. The circuit has inputs for receiving a channel change stream and a normal stream. The circuit further includes a multiplexer, a memory device, and a picture element detector. The multiplexer is for transmitting the channel change stream to a customer premises equipment (CPE) device in response to a channel change request from the CPE device. The memory device is for storing a flag that is set in response to the channel change request from the CPE device. The flag is set to request detection of a picture element in the normal stream. The picture element detector is for detecting the picture element in the normal stream subsequent to transmitting the channel change stream. The multiplexer transmits the normal stream to the CPE device in place of the channel change stream once the picture element is detected in the normal stream.

1 . A circuit for enabling a channel change in a digital network, the circuit having inputs for receiving a channel change stream and a normal stream, the circuit further comprising: 
 a multiplexer for transmitting the channel change stream to a customer premises equipment (CPE) device in response to a channel change request from the CPE device;    a memory device for storing a flag that is set in response to the channel change request from the CPE device, the flag being set to request detection of a picture element in the normal stream; and    a picture element detector for detecting the picture element in the normal stream subsequent to transmitting the channel change stream,    wherein said multiplexer transmits the normal stream to the CPE device in place of the channel change stream once the picture element is detected in the normal stream.    
   
   
       2 . The circuit according to  claim 1 , wherein the picture element is a memoryless picture element.  
   
   
       3 . The circuit according to  claim 1 , wherein the channel change stream includes more picture elements than the normal stream.  
   
   
       4 . The circuit according to  claim 1 , wherein the flag stored in the memory device is reset, when the picture element is detected in the normal stream.  
   
   
       5 . The circuit according to  claim 1 , further comprising a variable delay device for delaying the normal stream prior to a transmission of the normal stream from the multiplexer to the CPE device.  
   
   
       6 . The circuit according to  claim 1 , wherein the circuit is implemented in a digital subscriber line access modem (DLSAM).  
   
   
       7 . The circuit according to  claim 1 , wherein the digital network is a digital subscriber line (DSL) network.  
   
   
       8 . The circuit according to  claim 1 , wherein the picture element comprises any of an I-slice, an I-picture, and an instantaneous decoder refresh (IDR) picture.  
   
   
       9 . In a circuit connected to a digital network and having inputs for receiving a channel change stream and a normal stream, a method for enabling a channel change in the digital network, the method comprising the steps of: 
 transmitting the channel change stream to a customer premises equipment (CPE) device in response to a channel change request from the CPE device;    setting a flag, in response to the channel change request from the CPE device, to request detection of a picture element in the normal stream;    detecting the picture element in the normal stream subsequent to transmitting the channel change stream; and    transmitting the normal stream to the CPE device in place of the channel change stream, once the picture element is detected in the normal stream.    
   
   
       10 . The method according to  claim 9 , wherein said picture element is a memoryless picture element.  
   
   
       11 . The method according to  claim 9 , wherein the channel change stream includes more picture elements than the normal stream.  
   
   
       12 . The method according to  claim 9 , further comprising the step of resetting the flag, when the picture element is detected in the normal stream.  
   
   
       13 . The method according to  claim 9 , further comprising the step of delaying the normal stream prior to a transmission of the normal stream from the circuit to the CPE device.  
   
   
       14 . The method according to  claim 9 , wherein the circuit is implemented in a digital subscriber line access modem (DLSAM).  
   
   
       15 . The method according to  claim 9 , wherein the digital network is a digital subscriber line (DSL) network.  
   
   
       16 . The method according to  claim 9 , wherein the picture element comprises any of an I-slice, an I-picture, and an instantaneous decoder refresh (IDR) picture.