In {HEAD ~ the system} according to an embodiment of the invention, the channel CH1 of the group of {TAIL ~ channels} 18 is, according to a defined protocol, utilized by a service SRV1 
In { HEAD ~ the system } according to an embodiment of the invention , the channel CH1 of the group of { TAIL ~ channels } 18 is , according to a defined protocol , utilized by a service SRV1
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH