System and method for reliable store-and-forward data handling by encoded information reading terminals

A data collection system comprising:

• a plurality of encoded information reading terminals, each having at least an encoded information reading device outputting decoded message data corresponding to an encoded message, the encoded information reading device selected from the group consisting of a bar code reading device, an RFID reading device, and IC card reading device, a hand held housing incorporating said encoded information reading device, at least one wireless communication interface, a memory device, and a battery;
• and
• a data collection server external to said encoded information reading terminal having at least one network interface capable of establishing communications with said plurality of bar code reading terminals, and being in communication with at least a database storing the decoded messages data collected by said terminals;
• wherein said data collection system is configured to support ad-hoc network connectivity between said encoded information reading terminals in order to increase the reliability of the delivery of said encoded message data to said data collection server;
• wherein each terminal of said plurality of encoded information reading terminals is configured, upon power up, to initialize in said memory a data structure for storing an outbound data queue for queuing data packets intended for delivery to said data collection server;
• wherein each terminal of said plurality of encoded information reading terminals is further configured, in response to a user interface action, to perform a data capture and decoding operation yielding captured data, followed by formatting said captured data into one or more data packets, each of said data packets comprising a header and a payload, and further followed by appending said one or more data packets to said outbound data queue;
• wherein each terminal of said plurality of encoded information reading terminals is further configured, in response to receiving a wireless message from one or more of said plurality of encoded information reading terminals, said message containing one or more data packets of said captured data, to append said one or more data packets to said outbound data queue;
• and
• wherein each terminal of said plurality of encoded information reading terminals is further configured to periodically ascertain the presence of data packets in said outbound data queue and upon detecting the presence of one or more data packets in said outbound data queue to perform a method of forwarding the data packets from said outbound data queue to at least one of said data collection server and one or more of said peer terminals;
• wherein each terminal of said plurality of encoded information reading terminals is further configured to forward the packets from said outbound data queue by:
• (i) reading a data packet from said outbound data queue;
• (ii) conditionally, upon ascertaining that said encoded information reading terminal has direct connectivity to said data collection server, sending said data packet to said data collection server and removing said data packet from said outbound data queue;
• (iii) conditionally, upon ascertaining that said encoded information reading terminal does not have direct connectivity to said data collection server, sending a wireless broadcast message to said peer terminals, followed by sending said data packet to one or more of said peer terminals which has sent a response message to said broadcast message and which satisfy a criteria for receiving data packets;
• wherein each terminal of said plurality of encoded information reading terminals is further configured for selecting a level of data redundancy in storing and forwarding said captured data within said data collection system;
• wherein said level of data redundancy is controlled by a first threshold number said first threshold number representing number of wireless network “hops” to be traversed by said data packet;
• wherein said encoded information reading terminal upon receiving said data packet from one of said peer terminals, decrements by one said number of wireless network “hops” to be traversed by said data packet;
• and
• wherein said encoded information reading terminal forwards said data packet to one or more of said peer terminals conditionally, upon satisfying the condition that the value of the number wireless network “hops” after executing said decrementing is more than zero.

A method of reliable store-and-forward data handling by an encoded information reading terminal operating in a system including an external data collection server and a plurality of peer terminals, comprising the steps of:

• upon power up, initializing in said memory a data structure for storing an outbound data queue for queuing data packets intended for the delivery to said data collection server;
• in response to a user interface action, performing a data capture operation yielding captured data, followed by formatting said captured data into one or more data packets, each of said data packets comprising a header and a payload, and further followed by appending said one or more data packets to said outbound data queue;
• in response to receiving a wireless message from one or more of said peer terminals, said message containing one or more data packets of said captured data, appending said one or more data packets to said outbound data queue;
• and
• periodically ascertaining the presence of data packets in said outbound data queue and upon detecting the presence of one or more data packets in said outbound data queue, forwarding the data packets from said outbound data queue to at least one of said data collection server and one or more of said peer terminals;
• wherein said forwarding the packets from said outbound data queue further comprises the steps of:
• (i) reading a data packet from said outbound data queue;
• (ii) conditionally, upon ascertaining that said encoded information reading terminal has direct connectivity to said data collection server, sending said data packet to said data collection server and removing said data packet from said outbound data queue;
• (iii) conditionally, upon ascertaining that said encoded information reading terminal does not have direct connectivity to said data collection server, sending a wireless broadcast message to said peer terminals, followed by sending said data packet to one or more of said peer terminals which has sent a response message to said broadcast message and which satisfy a criteria for receiving data packets;
• wherein said criteria for receiving data packets includes creating a wireless network snapshot comprising said responses received from said plurality of encoded information reading terminals;
• followed by sorting said wireless network snapshot in the order of the connectivity of the peer terminal originating said response message to said data collection server, amount of memory available for storing said data packets at the peer terminal originating said response message, and the battery life expectancy of the peer terminal originating said response message;
• and followed by transmitting said one or more data packets to said one or more peer terminals in the order of said sorted responses.