Communication system for transmission of link layer datagram over a wireless network
A network controller for facilitating roaming of a mobile wireless communications device between access points communicates with at least one access point over a wired network which, in turn, communicate with a mobile wireless communications device over a wireless network. The network controller includes a data processing system including a protocol stack that facilitates a communication session between the mobile device and a network device on the wired network, and a session table identifying session information for each said communication session. The session information identifies the current access point with which the mobile device is currently associated. The protocol stack updates the session table from session information received from the current access point, maintains a first virtual circuit with the network device, maintains a second virtual circuit with the current access point, and bridges communication between the virtual circuits in accordance with the session information.
1. An access server for facilitating communication of electronic data between a network resource and a wireless communications device, the access server comprising:
a data processing system in communication with a network resource via a wired network and in communication with the wireless communications device via a wireless network, the data processing system including a protocol stack comprising:
(i) a protocol layer comprising a message processor for formatting the electronic data into at least one transport layer data segment, and a message monitor for formatting the at least one transport layer data segment into at least one link layer datagram, the message monitor being configured to monitor transmission of the link layer datagram over the wireless network, and to initiate retransmission of an unsuccessfully transmitted link layer datagram after a retransmission interval of magnitude which increases after a predetermined number of unsuccessful retransmission attempts of the unsuccessfully transmitted link layer datagram, each transport layer data segment and link layer datagram having a respective header, the transport layer header and the link layer header having a combined length less than a TCP/IP header.
2. The access server according to claim 1 , wherein the message monitor monitors an acknowledgement of a receipt of the link layer datagram from the wireless communications device.
3. The access server according to claim 2 , wherein the retransmission interval of magnitude is initially set to a running average of acknowledgement times for link layer datagrams successfully transmitted to the wireless communications device.
4. The access server according to claim 1 , the protocol stack comprises:
(ii) a first physical protocol layer in communication with the protocol layer for facilitating communication of datagrams over the wireless network;
(iii) a second physical protocol layer for facilitating communication of the datagrams over the wired network; and
(iv) an application protocol layer in communication with the intermediate protocol layer and the second physical protocol layer for mapping the electronic data between the wireless communications device and the network resource.
5. The access server according to claim 1 , wherein the message monitor layer is configured to increase the retransmission interval until a maximum upper limit is reached, and to maintain the retransmission interval at that maximum upper limit until the unsuccessfully transmitted on datagram is successfully transmitted.
6. The access server according to claim 5 , wherein the transport layer header includes a session number transport layer parameter identifying a data format of the electronic data, and the data processing system is configured to map the electronic data between the wireless communications device and a process on the wired network in accordance with the session number.
7. The access server according to claim 6 , wherein the transport layer header includes a radio address transport layer parameter uniquely associated with the wireless communications device, and the data processing system is configured to map the electronic data between the wireless communications device and the process in accordance with the radio address.
8. A method of electronic data communication between a network resource associated with a wired network and a wireless communications device associated with a wired network via an access server associated with the wired network, the access server having a communications protocol stack including a message processor and a message monitor, the method comprising the steps of:
at the message processor, formatting the electronic data into at least one transport layer data segment;
at the message monitor, formatting the at least one transport layer data segment into at least one link layer datagram, each transport layer data segment and link layer datagram having a respective header, the transport layer header and the link layer header having a combined length less than a TCP/IP header;
at the message monitor, monitoring transmission of the link layer datagram over the wireless network, and initiating retransmission of an unsuccessfully transmitted link layer datagram after a retransmission interval of magnitude which increases from that magnitude after a predetermined number of unsuccessful retransmission attempts of the unsuccessfully transmitted link layer datagram.
9. The method according to claim 8 , comprising:
at the message processor, extracting message data from the received at least one transport layer data segment.
10. The method according to claim 8 , comprising:
at an application protocol layer, mapping message data between the mobile wireless communications device and the network resource.
11. The method according to claim 8 , comprising:
in the message monitor, monitoring an acknowledgement of a receipt of the link layer datagram from the wireless communications device.
12. The method according to claim 11 , wherein the retransmission interval of magnitude is initially set to a running average of acknowledgement times for link layer datagrams successfully transmitted to the wireless communications device.
13. The method according to claim 8 , wherein the step of increasing the retransmission interval comprises increasing the retransmission interval until a maximum upper limit is reached, and maintaining the retransmission interval at that maximum upper limit until the unsuccessfully transmitted datagram is successfully transmitted.
14. The method according to claim 13 , wherein the transport layer header includes a session number transport layer parameter identifying a data format of the electronic data, and the mapping step comprises mapping the message data between the wireless communications device and a process on the wired network in accordance with the session number.
15. The method according to claim 14 , wherein the transport layer header includes a radio address transport layer parameter uniquely associated with the wireless communications device, and the mapping step comprises mapping the message data between the wireless communications device and the process in accordance with the radio address.