Wednesday, January 2, 2008

GPRS Wireless Solutions

General Packet Radio Service (GPRS) is a mobile data service available to users of GSM mobile phones. It is often described as "2.5G", that is, a technology between the second (2G) and third (3G) generations of mobile telephony. It provides moderate speed data transfer, by using unused TDMA channels in the GSM network. The maturity of the GPRS system has made it suitable for use as a transport medium for remote monitoring of utility assets such as pipelines, dams, pumping stations and where network flow and pressure measurement is required across a wide area (e.g. district or nationally).



GPRS is different from the older GSM Circuit Switched Data (or CSD) connections that have been popular in the last few years. In CSD, a data connection establishes a circuit, and reserves the full bandwidth of that circuit during the lifetime of the connection. GPRS is packet-switched which means that multiple users share the same transmission channel, only transmitting when they have data to send. This means that the total available bandwidth can be immediately dedicated to those users who are actually sending at any given moment, providing higher utilisation where users only send or receive data intermittently. Web browsing, receiving e-mails as they arrive and instant messaging are examples of uses that require intermittent data transfers, which benefit from sharing the available bandwidth. Point to multi-point remote monitoring systems found in water utility systems also suit this, where historical data can be logged and retrieved periodically (e.g. every hour) for analysis. With suitable event messaging critical alarms and conditions can be sent between the regular datalog retrievals.

No comments: