M2M Connection via Mobile Network
The widespread availability of cellular data networks presents another choice for machine-to-machine (M2M) communication today. Mobile telephony can be used to establish access to many sites where it is difficult to place land lines, such as in offshore applications, in the mountains, on the roof of a building, or by a highway. Whether used in location tracking devices, mobile Ethernet gateways, or for wireless data collection, cellular M2M offers mobility, encryption, more location options, and easier installation in a single package. For many situations, cellular M2M presents advantages that cannot be matched by hard wiring solutions, analog carriers, or satellite connections.

Cellular Network Technology
Modern wireless technology connects more than 2 billion cell phone users worldwide, using more than four times as many devices to manage connections. In different areas and countries, cellular operators offer different services. GSM is used almost everywhere, with upgraded service possible through GPRS and EDGE. Whereas GSM is considered 2G, GPRS is sometimes called 2.5G, and EDGE may be considered 2.75G. EDGE stands for "enhanced data rate for GSM evolution" and provides significantly better data transmission speeds. As for 3G, WCDMA/UMTS is the leading protocol for current GSM operators. In addition to GSM, there are also CDMA / CDMA2000 systems implemented in part of US, Australia, Japan, South Korea and so on, providing both voice and data services. The different systems compare as follows.

CSD Data Connection
CSD (Circuit Switched Data) is the original form of data transmission developed for GSM systems. With a single radio time slot, CSD can transmit data at 9.6 to 14.4 Kbit/sec to both the GSM network and the PSTN switching subsystem over a direct call. Most of the time, transmission is initiated by standard AT commands. Since CSD provides direct modem access to remote devices, system extensions can be used without requiring the installation of cables and data lines. CSD overcomes the limitations of hard wiring and inaccessible terrain for easier, more flexible data collection and monitoring.

GPRS IP Connectivity
GPRS is packet-switched, which means that multiple users share the same transmission channel. It transmits only when there is outgoing data. At any moment, the available bandwidth can be dedicated immediately for users that are sending or receiving data. In general, a GPRS network can be viewed as a special IP network that offers IP connectivity to IP terminals. Devices such as PCs, embedded computers, and PPP-enabled PLCs can be easily connected to the IP network and the Internet.