Method and apparatus to improve SCDMA headroom
First Claim
1. A method of improving headroom in a digital data communication network, wherein data is transmitted over a plurality of logical channels, the method comprising:
- determining that a remote transceiver has a headroom problem;
dividing a total transceiver power of the remote transceiver among fewer logical channels than the plurality of logical channels; and
transmitting on each of the fewer logical channels with sufficient power to overcome the headroom problem.
8 Assignments
0 Petitions
Accused Products
Abstract
A method of determining when cable modems in a distributed digital data delivery service over cable TV hybrid fiber coaxial cable network have a headroom problem and resolving said problem. The method involves measuring the burst power from each cable modem, and if the burst power is too low, requesting the cable modem whose burst power is too low to increase its transmit power, and keeping track of which modems have been requested to increase their power. If a predetermined number of requests to increase power have not resulted in the cable modem transmitting with sufficient power for reliable reception, the cable modem is listed as having a headroom problem. Subsequent requests for upstream bandwidth from all modems with headroom problems are analyzed to determine if the requested burst size is too large and will result in a headroom problem. If so, a calculation as to the maximum number of spreading codes that each modem with a headroom problem can simultaneously transmit on without a headroom problem. The requested burst is then broken down into smaller burst fragments, and appropriate upstream minislot assignments adequate to transmit the burst fragments are made and sent to the cable modem.
-
Citations
31 Claims
-
1. A method of improving headroom in a digital data communication network, wherein data is transmitted over a plurality of logical channels, the method comprising:
-
determining that a remote transceiver has a headroom problem; dividing a total transceiver power of the remote transceiver among fewer logical channels than the plurality of logical channels; and transmitting on each of the fewer logical channels with sufficient power to overcome the headroom problem. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for improving headroom in a digital data communication network having a headend transceiver, the method comprising:
-
obtaining a request for a burst to the headend transceiver from a remote transceiver; calculating how many burst fragments to divide the burst to make each burst fragment sufficiently small such that the burst can be transmitted with a sufficiently small number of spreading codes to reduce a headroom problem; and authorizing transmission of burst fragments, wherein each burst fragment is sufficiently small such that a sufficiently small number of codes are mapped to the burst fragment to reduce a headroom problem. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A cable modem termination system comprising:
-
a receiver configured to obtain a request for a burst from a remote transceiver; a computer coupled to the receiver; and a transmitter coupled to the computer, wherein the transmitter is configured to transmit an authorization of transmission of burst fragments, wherein each burst fragment is sufficiently small such that a sufficiently small number of codes are mapped to the burst fragment to reduce a headroom problem. - View Dependent Claims (22, 23, 24, 25)
-
-
26. A cable modem termination system comprising:
-
a receiver configured to receive a burst from a remote transceiver; a computer coupled to the receiver; and a transmitter coupled to the computer, wherein the transmitter is configured to send to the remote transceiver a restricted number of upstream logical channels which will reduce a headroom problem. - View Dependent Claims (27, 28, 29, 30, 31)
-
Specification