Upstream transmission profiles for a DOCSIS or DOCSIS-like system
A message structure is provided for assigning transmission profiles to individual modems for modem transmissions in an upstream direction, on a modem by modem basis. The profiles define a set of transmission parameters, e.g., forward error correction information, symbol rate, frequency, modulation type, etc. that the modem should use to optimize their transmission in the upstream direction in order to maximize throughput. The invention is applicable to both wireless and land-based communications systems, particularly those adhering to the Data-Over-Cable Service Interface Specifications (“DOCSIS”)—Radio Frequency Interface Specification standard, or other standards which are analogous to the DOCSIS standard. The message structure can consist of two parts—a first part that defines a plurality of different types of transmission profiles, and a second part that assigns a particular profile to a modem. In a DOCSIS embodiment, the first part is contained in a UCD packet and the second part is contained in a MAP packet.
1. A method of connecting a plurality of modems to a network over a transmission medium, in which the transmission medium has different transmission characteristics for different modems in said plurality of modems, comprising the steps of:
a) transmitting messages to said modems wherein said messages assign a specific transmission profile to said modems based on transmission characteristics for said modems on a modem-by-modem basis; wherein said messages comprise a first portion defining a plurality of transmission profiles and a second portion assigning a transmission profile for said modems to use, and wherein said messages are issued in an iterative fashion specifying increased transmission speeds for said modems until an optimal level is reached;
b) configuring said modems in accordance with said transmission profiles; and
c) said modems transmitting in an upstream direction in accordance with said transmission profiles.
2. A node in a network performing step a) of claim 1 .
3. The node of claim 2 , wherein said node comprises a cable modem termination system.
4. A network node optimizing transmission from remote modems to said node over a communications medium, comprising:
a memory storing a plurality of defined transmission profiles for said remote modems, said transmission profiles identifying particular upstream transmission characteristics that said modems may potentially use when transmitting in a direction from said remote modems to said node; and
a software process for generating at least one packet for transmission to said remote modems, said at least one packet containing said defined transmission profiles and assigning one of said transmission profiles to an individual one of said modems; and
an interface for transmission of said at least one packet from said node to said remote modems;
wherein said at least one packet comprises a first portion defining a plurality of transmission profiles and a second portion assigning a transmission profile for said modems to use, and wherein said at least one packets are issued in an iterative fashion specifying increased transmission speeds for said modems until an optimal level is reached.
5. The node of claim 4 , wherein said node comprises a cable modem termination system.
6. The node of claim 4 , wherein said node comprises a node of a wireless network.
7. The node of claim 4 , wherein said node comprises a node of a communication system compliant to a DOCSIS standard.
8. The node of claim 7 , wherein said at least one packet comprises an upstream channel descriptor packet containing said defined transmission profiles and a bandwidth allocation map packet containing a field assigning one of said transmission profiles to each of said modems.