Adaptive synchronous media access protocol for shared media networks
In some embodiments of the present invention, asynchronous network nodes and synchronous network nodes coexist on a shared media network.
1. A method implementable on a transmitter of a shared media network, the method comprising:
during scheduled contention and non-contention transmission opportunities, listening to a medium of a shared media network for the presence of interference by unscheduled transmissions;
delaying initiation of a scheduled transmission if there is interference and then transmitting once said network is idle according to an allocated transmission opportunity or until the end of a contention transmission opportunity;
upon delayed transmission, adjusting timing of remaining scheduled non-contention transmission opportunities; and
resolving any collisions.
2. The method according to claim 1 and also comprising dynamically adjusting timing of those synchronous transmission whose transmission start times exceed their scheduled times.
3. The method according to claim 2 and wherein said dynamically adjusting comprises allowing said adjusted synchronous transmissions to continue transmission into unallocated transmission opportunities.
4. The method according to claim 2 and wherein said transmitting comprises:
requiring transmissions within a transmission opportunity (TXOP) to occupy an amount of bandwidth allocated to said TXOP irrespective of when said TXOP actually starts; and
requiring that transmissions within an unallocated TXOP not extend beyond the scheduled end-time of the unallocated TXOP, regardless of a time at which the unallocated TXOP began.
5. The method of claim 1 wherein each said scheduled transmission opportunity is dedicated to a node.
6. The method of claim 5 and wherein said node belongs to a group of nodes and wherein at least one said scheduled transmission opportunity is dedicated to said group of which said node is a member.
7. The method of claim 6 , and wherein said transmitting comprises:
transmitting said transmission for a length of time not longer than a duration of said scheduled transmission opportunity.
8. The method of claim 5 and also comprising:
abandoning collision resolution between nodes colliding in their transmissions on said shared media network during a timed media access period of a specified length when not enough time is left of said media access period for a transmission by one of said nodes.