Traditional Wireless Mobile Communication

The Cellular device has evolved a lot and it has become part of everyone’s life as a hands − on device. Now, most people are access to mobile technology that uses Global Standard for Mobile Communication which is termed wireless mobile communication. The First designed Mobile phones use radio waves. Cellular communication comes under the network technology comprising cells and base stations. The usage of it is by dividing the area into smaller cells and reusing the frequency. In this article, we will study the concept of the Traditional Wireless Mobile Communication.

The Traditional analog system is designed for the transmission of voice in analog form rather than a digital signal. Motorola DynaTAC 8000X is the first commercially introduced wireless mobile phone in the 1980s and the design of this device is more like a brick.

Wireless Mobile Communication

Global Standard for Mobile Communication

In an Analogue system, the voice signals are transmitted in an analog form and have some disadvantages. After that, Digital Signal Processing chips came into the track. It is a microprocessor for mobile communication for the baseband design and lower layer protocols but they are costly to install and maintain.

The Time Division Multiple Access and Code Division Multiple Access are proposed for a fully digital system to reduce the setup cost and improve efficiency. To avoid the confusion between CDMA and TDMA, GSM is agreed upon as a standard for mobile communication and GSM is a form of TDMA.

GSM is Preferred as it uses more bits per second for transmitting the voice signal in digital form. It is the first accepted standard by European and finally a world standard for Wireless Mobile Communication.

Advantages of Digital Systems (GSM) over Analog (Cellular)

Some of the advantages are traffic-free data transmission in signaling, levels of interference are low, combining the transmission and switching and a digital system will handle increased capacity.

GSM Systems

GSM is used due to its functions, recommendations, and uses over other systems. It is divided into three systems namely,

• Mobile Station (MS)

• Base Station Sub System (BSS)

• Operation and Support System (OSS)

1. Mobile Station (MS)

The User’s equipment like cell phone, SIM (Subscriber Identity Module), and software needed for communication are included. The Primary components of GSM Mobile Stations (MS) are,

• SIM Card

• Mobile Termination

• Terminal Adapter

• Terminal Equipment

• SIM Card − In a cellular device, Subscriber Identity Module is a removable memory circuit that stores the user’s information and authentication protocol.

• Mobile Termination − Error detection or correction, radio transmission, and speed encoding or decoding are the functions of Mobile Termination.

• Terminal Equipment − Any device like a mobile phone can be connected to the Mobile station via terminal equipment.

• Terminal Adapter − It provides access to the Mobile Termination

2. Base Station Sub System (SS)

The Base Station Subsystem is a larger unit that is connected to two or more Base station Controllers. They are installed in a particular area and cover all the functions in that area. Mobile Switching System (MSS) controls the BSS for managing the radio network. The basic components of the subsystem are −

• Base Station Controllers

• Base Transceiver Stations

BSC

Base Station Controller is an Intermediate element between the BTS and Telecommunication that controls primarily the radio network.

Functions of BSCs

The incoming and outgoing calls are from the mobile stations through the Base Station Controller. It controls all functions of the Base Transmitter and Receiver Station, the handover, and has a large capacity. BSC monitors the quality and allocation of the radio resources in the network.

To have a proper call connection without any quality error or call cut, they must be synchronized. The path of synchronization is as follows,

$$\mathrm{MSC\longrightarrow\:BSC\longrightarrow\:BTS}$$

BTS

Base Transceiver Station controls and monitors the air interface. In the Open System Interconnection model, air interfaces are included in the physical and Data link layers.

Radio communication is the common air interface between the systems. It generally needs 120 parameters to complete the task.

Each cell in the network receives services using this station. The base Transceiver station is controlled by the Base Station Controller.

Functions of BTS

Call-related information needs to be performed in order. Encryption and Decryption of data or Cipher and Decipher of data for transferring the secured resources without leaking and damaging.

To perform speech processing by converting either from analog to digital or digital to analog, channel coding for error protection, rearranging the code for secure transmission, and checking whether it fits the time slot. It is also used for the modulation and demodulation of signals.

3. Operation and Support System

Working on the wireless system, operations, and maintenance is the most important phenomenon. So, every piece of equipment in the switching system is connected to the OSS and it also controls and monitors them.

The operation and support system is implemented using the Operation Maintenance Centre. Various services maintained by the GSM networks are local, regional, and centralized operations. Using this system, users can have cost-effective support for the above services.

Functions of GSM OSS

The primary functions of handling calls both incoming and outing calls and mobility management of networks. To manage the data of subscribers such as name, address, billing cycle, and plan.

It performs or handles the switching of calls between cellular to cellular and between cellular to Public switched Telephone Networks. The two divisions of OSS are,

• Database

• Switches

In Early times, a wired connection is used for the communication between the caller and the calling person who have a permanent location. But in wireless, we must deal with the mobility of subscribers that uses radio waves for transmission. The task of wireless communication is to find where and who the subscriber is and what services they want.