Electrosmart.Net

GSM In Telecommunications

Global Systems for Mobile Communications [GSM] is a mobile network standard used for voice and SMS some low-bit-rate circuit-switched data services. It is current deployed by more than 90 percent of the worlds mobile service providers. Only Japan and South Korea, rely exclusively on other standards.

Since initial introduction, GSM has continued to evolve to support higher speed packet data services.

GPRS - General Packet Radio Service - introduced packet-data capabilities.

EDGE - Enhanced Data Rates For GSM Evolution - greatly extended the capabilities of packet-data services. EDGE technology, which is backward compatible with GPRS, offers up to a 200% increase in data bit rates.

By November 2005, 121 GSM operators were offering commercial EDGE-based services in 70 countries, and 172 operators in 92 countries had committed to providing EDGE.

The future of GSM depends upon:

Low total cost of ownership (TCO)
Deployment of Enhanced General Packet Radio Service [EGPRS] in every network.

Thse challenges are currently being addressed using GSM transport or backhaul.

Network Operations Costs

The largest cost components of a GSM network:

Deployment of the network
Transmission to radio base station (RBS) sites.

Traditional transmission from RBSs to a base station controller (BSC) is done using static time-division multiplexing (TDM) circuits. TDM does not transmit bursty data traffic efficiently or adapt easily to low-cost transport technologies, such as IP and Ethernet. IP and Ethernet are more efficiently deployed over copper, fiber, and micro-wave networks.

However, recent developments in GSM transport and switching technologies promise to overcome these issues, making GSM suitable to provide services both to low-revenue users and to users of high-speed data services.

Packet Abis

Ericsson's Packet Abis is a new protocol for transferring data over the Abis link.The air interface of the solution sends all traffic (voice, data and signaling) in packets over Abis with a minimum of repacking and reformatting. When used over TDM transport networks it optimizes transport of IP or Ethernet.

EDGE

GSM/EDGE is another standard that also offers high-performance voice and data services. Proposed technology enhancements will improve:

Average and peak bit rates - improves web browsing and file downloads
Latency - improves conversational services VoIP and enhanced Push to talk over Cellular [PoC], as well as online gaming service
Service coverage - both voice and packet-data benefit from terminals being always connected to the most appropriate base station
Spectrum efficiency - operators can increase traffic volumes without compromising quality

Specific solutions include:

Dual-antenna terminals
Multicarrier EDGE
Mobility enhancements
Reduced transmission time intervals
Higher-order modulation
New coding schemes.

Combined, these solutions fulfil the requirements set by 3GPP.

Improving Service Performance

To allow GSM/EDGE to facilitate multimedia services and improve service performance and service continuity, major vendors and many operators have pledged support for a continued evolution, standardized in 3GPP.

The general objectives are to:

Improve service performance
Provide more efficient bearers
Ensure seamless operation or service continuity between GSM/EDGE and WCDMA networks

Faster initial response from the network especially benefits conversational services and applications with limited system interactivity prior to uploading or downloading application data [WAP, MMS and FTP]. 3GPP solutions have proposed access times of less than 500ms.

As GSM/EDGE equipment is very large, Ericsson has tried to minimize technology enhancements on base station hardware. Therefore, the proposed solutions assume the same (current) network architecture and have no impact on transceiver units and other base station hardware. Only radio network software and terminals will need to be updated.

Next: EDGE - Enhanced Digital