초록 ▼

A collision resolution system and method for enhanced non-contact automated data collection. The data collection system generally includes a plurality of portable fare tags or token ("smart") cards and a stationary target terminal. Each tag exchanges a series of messages with the target terminal to

A collision resolution system and method for enhanced non-contact automated data collection. The data collection system generally includes a plurality of portable fare tags or token ("smart") cards and a stationary target terminal. Each tag exchanges a series of messages with the target terminal to establish a communication link for the transfer of financial or other data. Concurrently, each tag and the target terminal process the messages to provide collision resolution, thereby ensuring that only one tag, at any instance, establishes the communication link with the target.

대표청구항 ▼

[ What is claimed is:] [1.] A system for providing contactless automated data exchange with collision resolution, comprising:at least two tags, each of said tags includingmeans for outputting a first tag message, after a first period of time, in response to a first target message and another first t

[ What is claimed is:] [1.] A system for providing contactless automated data exchange with collision resolution, comprising:at least two tags, each of said tags includingmeans for outputting a first tag message, after a first period of time, in response to a first target message and another first tag message, after a second period of time, in response to a second target message, andmeans for outputting a second tag message in response to a third target message; anda target, includingmeans for outputting said first target message,means for determining if said first tag message received by said target is valid,means for outputting said third target message if said first tag message by said target is valid, andmeans for outputting said second target message if said first tag message received by said target is invalid;wherein each of the first and second periods of time is a random wait period determined by each of said tags and is a random multiple between 0 and 7 of a predetermined slot time having a duration of approximately 0.3 milliseconds and exceeding a round-trip time for transmitting a message between the target and one of the tags.