A mobile phone is a portable device. Mobile communication is based on cellular networks. A cellular network is nothing but a radio network. In a cellular network, land is divided into areas called cells. Every cell in the network has a transmitter and receiver known as the base station of the cell site. Each cell in the network uses a different frequency for the transmission of signals. When joined together, these cells provide radio coverage over a large geographical area. The network of cells enables the mobile device to communicate even if it is moving from one cell to another via base stations.
The mobile industry has grown dramatically in the last decade, both in terms of mobile communication technology and subscribers.
The first system offering mobile communication service was introduced in the 1940s and early 1950s in the US. In Europe, these single-cell systems were severely constrained by restricted mobility, low capacity, limited service, and poor speech quality. Also, the equipment was heavy, bulky, expensive, lighter, and susceptible to interference.
The use of semiconductor technology and microprocessors made mobile systems smaller, lighter, and more sophisticated.
GSM (global mobile phone system), also known as “unicatis ann,” is an open digital cellular technology that transmits mobile voice and data service. The GSM emerged in the early 1970s from Bell Laboratories’ concept of a cell-based mobile radio system. GSM is the most recent standardization effort, established in 1982 to create a common European mobile telephone standard. The GSM standard is the most widely accepted standard and is implemented globally.
GSM allows for eight simultaneous calls on the same radio frequency and uses “narrowband” TDMA, the technology that enables digital transmission between a mobile phone and a base station. With TDMA, the frequency band is divided into multiple channels, which are then stacked together into a single stream, hence the term “narrowband.”
The users of GSM use subscriber identity module (SIM) cards for their connection with the service provider. SIM cards are small in size with removable memories and hold a lot of data and identification numbers, which are required to access any wireless service provider.
Advantages of GSM
- On the market, there are numerous handsets and service providers. Hence, the buyer can choose from a variety of options.
- They come with a variety of plans with cheaper call rates, free messaging facility, limited free call and so on.
- The quality of calling GSM is better and also better secured than CDMA.
- A number of value-added services such as GPRS (general packet radio service) are making GSM a perfect choice.
- The consumption of power is less in GSM mobiles.
- With the tri band and GSM, one can use the phone anywhere around the world.
- The SIM card or subscriber recognised unit card which transmits subscribers and exchange info, secures purchaser info.
- SIM cards also permit consumers to handover their subscription info and telephone book info from one receiver to add at any period.
- Clienteles are capable to Roam global without alerting their device or their facility plan.
- Less signal distortion inside the building.
Disadvantages in GSM
- Per unit charge of roaming calls is higher in GSM than in CDMA.
- Calls made through GSM mobiles can be tempered.
- If the SIM gets lost, one can lose all the data. if the same is not saved in the phone.
- Signals can be detected easily in GSM compared to CDMA.