Abstract: In order to discourage compression of video and other visual image signal data that accompanies unauthorized reproduction, distribution and storage of such data, the signal data is modified in a manner to be essentially imperceptible but which, when compressed and then decompressed, causes the signal quality to be unacceptable. In one approach, the visual signal is modified directly. In another approach, the signal is first transformed into the same domain where a compression-decompression algorithm encodes and decodes the data, and then the transformed signal is modified so that the quality of the visual signal when decompressed and displayed is unacceptably degraded.

Abstract: A method of searching for a predefined code in a bit stream, the method comprising initiating a first search for correlation of the bit stream with a reference code applied to the bit stream at a first plurality of different times according to a first resolution to produce a first set of correlation values and associated times. Then a second search is initiated for correlation of the bit stream with the reference code applied to the bit stream at a second plurality of different times to produce a second set of correlation values and associated times, the reference code being offset in time from a maximal correlation value of the first set such that the reference code is applied to the bit stream at times other than times of the first plurality. Then, out of the first and the second sets a maximal correlation value is selected for use in calculating a strength of the predefined code in the bit stream.

Abstract: In order to discourage compression of video and other visual image signal data that accompanies unauthorized reproduction, distribution and storage of such data, the signal data is modified in a manner to be essentially imperceptible but which, when compressed and then decompressed, causes the signal quality to be unacceptable. In one approach, the visual signal is modified directly. In another approach, the signal is first transformed into the same domain where a compression-decompression algorithm encodes and decodes the data, and then the transformed signal is modified so that the quality of the visual signal when decompressed and displayed is unacceptably degraded.

Abstract: A method of searching for a predefined code in a bit stream, the method comprising initiating a first search for correlation of the bit stream with a reference code applied to the bit stream at a first plurality of different times according to a first resolution to produce a first set of correlation values and associated times. Then a second search is initiated for correlation of the bit stream with the reference code applied to the bit stream at a second plurality of different times to produce a second set of correlation values and associated times, the reference code being offset in time from a maximal correlation value of the first set such that the reference code is applied to the bit stream at times other than times of the first plurality. Then, out of the first and the second sets a maximal correlation value is selected for use in calculating a strength of the predefined code in the bit stream.

Abstract: In one embodiment a system is provided for multirate communications allowing for different data rates for each data unit on a channel, including both data units from different mobile units and from the same mobile unit. A sending unit preferably begins by determining the rate at which to start communications, and monitors, for example by use of an RSSI detector, for an indication that the rate should be changed. A rate adjustor implements the change, and can make changes as frequently as every data unit. The encoder applies the appropriate rate and inserts a rate indicator indicative of the data or encoding rate, and sends the data unit. On receiving data units, the receiving unit first determines the rate for each data unit or group of units, then appropriately decodes the data unit(s). As a result, the actual data throughput can be adjusted to permit optimized throughput.

Abstract: The disclosed system is capable of allocating plural subchannels based on user data priority. In one embodiment, after receiving a system parameters such as a current priority level from a base station, a subscriber determines whether to send an access request for plural subchannels. Upon receipt of the access request(s), the system determines from the access request(s) whether to allocate the subchannel(s) to the subscriber. Further access requests are received periodically and scheduled, and when a higher priority message is received, completion of a lower priority message is deferred and the higher priority request allocated. Thus, an improved access procedure is provided accommodating multiple priority requests in an efficient manner. In a further embodiment, the system parameters include persistence/probability values for each service priority level, and each transmitting unit applies the appropriate value for the data priority to be sent in determining when to send an access request.

Abstract: The disclosed system is capable of allocating plural subchannels based on user data priority. In one embodiment, a subscriber determines the throughput it would like and fragments a data packet in that number of service data units, and requests that number of subchannel allocations from a serving base station. Upon receipt of the access request(s), including any priority indicators, the system determines from the access request(s) whether to allocate the subchannel(s) to the subscriber. Further access requests are received periodically and scheduled, and when a higher priority message is received, completion of a lower priority message is deferred and the higher priority request allocated. Thus, an improved access procedure is provided accommodating varying throughput rates with a more robust transfer because of the packet fragmentation and multiple-subchannel transfer.