摘要:
The systems and methods disclosed herein relate to digital data communication systems, and more particularly, the systems and methods relate to systems and methods for facilitation digital communication between a first modem equipped facsimile machine and a second modem equipped facsimile machine. In one example, the system has the second modem equipped facsimile machine system or a first modem equipped facsimile machine that utilizes a modem for data communication, and a telemetry device with a processor for communicating with the first modem equipped facsimile machine and a digital cellular radio for communicating with the processor. The processor relays digital data from the first modem equipped facsimile machine to the digital cellular radio and the digital cellular radio transmits the digital data to the second modem equipped facsimile machine system. This system allows a user to transmit the digital data representing a document. This system facilitates bi-directional communication between a first modem equipped facsimile machine connected to a digital cellular or wireless network via the first telemetry device and a second modem equipped facsimile machine connected to a land (POTS) telephone line or wireless network via the second telemetry device. Data transport over PSTN or wireless networks can be via a circuit-switched or packet data connection.
摘要:
Disclosed herein are systems, apparatus and methods for (1) detecting codes assigned to utility meters that have frequently changing codes and (2) translating codes between the central data acquisition system that contains a fixed identification code for each utility meter and utility meters that have frequently changing identification codes.
摘要:
In one embodiment, after establishing a packet data connection (1XRTT or GPRS) and obtaining an IP address, the remote data device registers with the proxy server using UDP packets. The remote data device periodically transmits UDP packets to the proxy server to maintain the registration and possibly any NAT/firewall translations (for the UDP session) in the cellular network. The proxy server is configured to listen on a different TCP port for the remote data device. This is a fixed port number for any given remote data device and is used for addressing the remote data device by the central data acquisition system that wants to access the remote data device. When the proxy server receives a TCP connection (from the central data acquisition system) on the port for a specific remote data device, the proxy server marks the remote data device as being busy and transmits a UDP message to the remote data device informing it that a connection is requested. If the proxy server does not receive a TCP connection from the remote data device, the proxy server transmits connection no-acknowledge message to the central data acquisition system, and marks the remote data device as being idle. Upon receipt of the connection request message, the remote data device establishes a TCP session with the proxy server. The proxy server establishes communication between the central data acquisition system and the remote data device. If the proxy server can establish communication, the proxy server terminates communication and marks the remote data device as being idle.