Roaming encoded information reading terminal

A portable encoded information reading (EIR) terminal for incorporation in a data collection system having a plurality of peer EIR terminals and a plurality of interconnected networks including one or more wireless networks, said EIR terminal associated with a home network having an associated address range, said home network being one of said plurality of networks, said EIR terminal configured to be associated with a care-of address when in communication with a foreign network other than said home network, said EIR terminal configured to provide IEEE 802.11-conformant wireless distribution system services, including association, disassociation, distribution, integration, and re-association, to said peer EIR terminals, said EIR terminal comprising:

• a central processing unit (CPU);
• a memory;
• an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• at least one wireless communication interface;
• wherein said EIR terminal is configured, when roaming from a first network of said plurality of networks to a second network of said plurality of networks, to maintain zero or more active communication sessions with at least one remote host computer using a home address belonging to said associated address range of said home network;
• and
• wherein said EIR terminal is further configured to transmit a registration request message to one of:
• a home agent having a home agent address and being in communication with said home network, a foreign agent in communication with said foreign network, said registration request message including said home address, said home agent address, and said care-of address.

A portable encoded information reading (EIR) terminal for incorporation in a data collection system having a plurality of peer EIR terminals and a plurality of interconnected networks including one or more wireless networks, said EIR terminal associated with a home network having an associated address range, said home network being one of said plurality of networks, said EIR terminal configured to be associated with a care-of address when in communication with a foreign network other than said home network, said EIR terminal configured to provide IEEE 802.11-conformant wireless distribution system services, including association, disassociation, distribution, integration, and re-association, to said peer EIR terminals, said EIR terminal comprising:

• a central processing unit (CPU);
• a memory;
• an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• at least one wireless communication interface;
• wherein said EIR terminal is configured, when roaming from a first network of said plurality of networks to a second network of said plurality of networks, to maintain zero or more active communication sessions with at least one remote host computer using a home address belonging to said associated address range of said home network;
• and
• wherein said EIR terminal is further configured to receive datagrams addressed to said care-of address.

A data collection system comprising:

• a plurality of interconnected networks including one or more wireless networks;
• a router configured to route datagrams between said plurality of networks and at least one remote host computer;
• a plurality of EIR terminals, each EIR terminal associated with a home network having an associated address range, said home network being one of said plurality of networks, each EIR terminal comprising a central processing unit (CPU), a memory, at least one wireless communication interface, and an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• wherein at least one EIR terminal of said plurality of EIR terminals is configured to provide IEEE 802.11-conformant wireless distribution system services, including association, disassociation, distribution, integration, and re-association, to said peer EIR terminals;
• wherein said at least one EIR terminal is configured, when roaming from a first network of said plurality of networks to a second network of said plurality of networks, to be associated with a care-of address when in communication with a foreign network other than said home network, and to maintain zero or more active communication sessions with said at least one host computer using a home address belonging to said associated address range of said home network;
• and
• wherein said at least one EIR terminal is further configured to transmit a registration request message to one of:
• a home agent having a home agent address and being in communication with said home network, a foreign agent in communication with said foreign network, said registration request message including said home address, said home agent address, and said care-of address.

A data collection system comprising:

• a plurality of interconnected networks including one or more wireless networks;
• a router configured to route datagrams between said plurality of networks and at least one remote host computer;
• a plurality of EIR terminals, each EIR terminal associated with a home network having an associated address range, said home network being one of said plurality of networks, each EIR terminal comprising a central processing unit (CPU), a memory, at least one wireless communication interface, and an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• wherein said at least one EIR terminal is configured, when roaming from a first network of said plurality of networks to a second network of said plurality of networks, to be associated with a care-of address when in communication with a foreign network other than said home network, and to maintain zero or more active communication sessions with said at least one host computer using a home address belonging to said associated address range of said home network;
• wherein said at least one EIR terminal is further configured to transmit a registration request message to one of:
• a home agent having a home agent address and being in communication with said home network, a foreign agent in communication with said foreign network, said registration request message including said home address, said home agent address, said care-of address;
• and
• wherein said home agent is configured to maintain a roaming buffer for buffering MAC frames addressed to said at least one EIR terminal, said home agent further configured to start buffering MAC frames addressed to said at least one EIR terminal in said roaming buffer responsive to a first triggering event, said home agent further configured to forward buffered MAC frames addressed to said at least one EIR terminal responsive to a second triggering event.

A data collection system comprising:

• a plurality of interconnected networks including one or more wireless networks;
• a router configured to route datagrams between said plurality of networks and at least one remote host computer;
• a plurality of EIR terminals, each EIR terminal comprising a central processing unit (CPU), a memory, at least one wireless communication interface, and an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• wherein said router is configured to maintain a network address translation (NAT) table, said NAT table comprising at least one NAT entry, said at least one NAT entry including an internal address associated with an EIR terminal of said plurality of EIR terminals;
• wherein said EIR terminal is further configured, when roaming from a first network of said plurality of networks to a second network of said plurality of networks, to maintain zero or more active communication sessions with said at least one host computer using an external address;
• and
• wherein said EIR terminal is configured to acquire a new internal address upon associating with a network of said plurality of interconnected networks.

A portable encoded information reading (EIR) terminal for incorporation in a data collection system having a plurality of peer EIR terminals and a plurality of interconnected wireless networks, said EIR terminal associated with a home network having an associated address range, said home network being one of said plurality of networks, said EIR terminal comprising:

• a central processing unit (CPU);
• a memory;
• an encoded information reading (EIR) device selected from the group consisting of:
• a bar code reading device, an RFID reading device, and a card reading device, said EIR device configured to perform one of:
• outputting raw message data containing an encoded message, outputting decoded message data corresponding to an encoded message;
• at least one wireless communication interface;
• wherein said EIR terminal is configured, to maintain zero or more active communication sessions with at least one remote host computer when roaming from a first network of said plurality of networks to a second network of said plurality of networks, said first network having at least one first network wireless access device selected from the group consisting of:
• a wireless access point (AP) and a wireless portal, said second network having at least one second network wireless access device selected from the group consisting of:
• a wireless access point (AP) and a wireless portal;
• and
• wherein said EIR terminal is further configured to disassociate with said first network and associate with said second network responsive to detection of a roaming process triggering condition selected from the group consisting of:
• receive signal strength indication (RSSI) of said first network wireless access device being too low;
• difference between RSSI of said first network wireless access device and said second network wireless access device being larger than a first pre-defined threshold;
• excessive interference or noise in said first network;
• excessive number of unsuccessful attempts to re-associate with said first network wireless access device;
• insufficient capacity of said first network wireless access device;
• and transmission errors exceeding a second pre-defined threshold.