PCS Architecture

PCS Architecture is a technique to develop a wireless network structure for personal communication.

It encompasses the various components and protocols that enable communication between devices in a wireless network.

The architecture includes base stations, mobile devices, and network infrastructure. Consequently, they all work together to provide seamless connectivity and communication services.

Moreover, PCS architecture enables efficient and reliable communication, allowing users to make calls, send messages, and access data seamlessly.

Additionally, the design optimizes network performance, enhances user experience, and supports various applications and services in a wireless environment.

PCS Architecture in Wireless Communication

PCS Architecture Diagram

Wireless technologies enable individuals to stay connected and communicate effectively, regardless of location.

Understanding each component's role within the system allows us to design an efficient and effective PCS architecture.

Additionally, PCS architecture divides itself into two main components: the wireline transport network and the radio network.

Wireline Transport Network

A wireline transport network transmits voice and data signals over physical cables.

This network also enables reliable and secure data communication, carrying large amounts of information over long distances.

Radio Network

A radio network is a system that connects different radio stations, enabling them to share content and broadcast to a larger audience.

Consequently, it allows stations to collaborate, exchange programming, and reach a wider range of listeners.

Ultimately, it plays a crucial role in connecting people through radio waves, providing diverse content.

Components of PCS Architecture in Mobile Computing

PCS architecture in Mobile Computing is a collection of components and services in which components communicate via interfaces.

It includes base stations, mobile devices, network infrastructure, and signal protocols that work together to ensure reliable and secure communication.

Components of PCS Architecture

Mobile Stations (MS)

MS refers to moveable devices in the radio network, such as cell phones, handsets, or portable devices installed on cars.

Subscriber Identity Module (SIM) and Mobile Equipment (ME) or Mobile Terminal are two components of MS (MT).

International Mobile Equipment Identity (IMEI) is the unique identifier associated with the ME, which manufacturers cannot modify after production.

When registering or subscribing to a network, SIM cards contain important information, including the International Mobile Subscriber Identity (IMSI), protected by a four- to eight-digit code (PIN).

Because it can't communicate with other MS in the network, an MS without a SIM is just an end terminal.

MS communicates with BSS via the Um Interface.

Small and large equipment interact to form a wireless network in PCS architecture.

There are many types of mobile devices, including handsets, devices mounted on vehicles, mobile towers, substations, and so on.

Base Station Subsystem (BSS)

The BSS communicates with the MS and the Network Switching Subsystem (NSS).

Two components divide the BSS:

• Base Transceiver Station (BTS)

The BTS consists of transceivers (transmitters and receivers) and signalling equipment, such as antennas in a cell.

Subsequently, by transmitting power, each BTS determines the cell's radius by positioning itself in the centre.

Signals from MS are sent and received through the UM interface by the BTS.

• Base Station Controller (BSC)

The BSC administers the radio resources within the group of BTS and performs handovers, radio channel setup, exchange function, control radio frequency power level, and frequency hopping.

Moreover, BCS communicates with other BTS via the A-bis interface, which uses Integrated Services Digital Network (ISDN) protocols.

Network Switching Subsystem (NSS)

NSS regulates the whole network by switching services and keeping the database of moving MS within the network.

• Mobile Services Switching Center (MSC)

MSC serves as a PSTN or ISDN switching node.

The Equipment Identity Register (EIR) database, the Authentication Center (AUC) database, and location register databases such as the HLR and VLR all contain information that MSC helps to manage.

By their IMEI number, EIR holds information on all valid mobile equipment in the network.

When someone reports a stolen MS or personal device, the database marks the IMEI invalid.

MSC handles mobile subscribers by switching services based on their unique identifiers, such as IMEI, by registering MS, authenticating MS, calling MS location, handover, and call routing.

• Home Location Register (HLR)

When an MS connects to a PCS network service, a record is made in the HLR database.

Even if MS is inactive, the HLR database includes MS's information, such as service provisioning information, authentication data, current location, and last location.

MS's home network fixes and stores HLR data.

Additionally, the HLR database is designed to function as a distributed database.

Logically, there is only one HLR for each network.

The signal address of VLR is used to store the MS location, and it regularly checks the MS location and relative BTS while maintaining the database.

Furthermore, AUC is a password-protected database containing a copy of the secret key stored in each MS SIM.

• Visitor Location Register (VLR)

The VLR database creates a record whenever an MS visits a PCS network other than their home network.

VLR keeps a temporary record of chosen information from an MS's HLR and makes services available to the MS at that place.

The system uses the VLR database to obtain MS information for call handling.

Operation And Support Subsystem (OSS)

It also keeps the traffic load within BSS in control.

By establishing connections between different components of NSS and BCS, OSS controls and monitors the architecture.

To establish a connection, one must follow a collection of rules known as protocols.

A cell is a radio coverage region that each BS in a radio network has.

MS can converse with one another both inside and outside the cell.

The BSC acts as an interface between the MSC of the Wireline Transport network and the BTS of the radio network.

Interfaces in PCS Architecture

The PCS architecture consists of four main types of interfaces.

Unified Message (UM) Interface

The first interface, which is essential for wireless communication between the mobile device and the base station, is known as Um.

Abis Interface

The second interface, called Abis, is crucial for connecting the base station and the base station controller, ensuring the seamless transmission of data and control signals.

A-Interface

The third interface, known as the A-interface, acts as a bridge between the base station controller and the mobile switching centre, facilitating the efficient exchange of voice and data traffic.

Signalling System 7 (SS7) / Service User Part (SUP)

Lastly, the Signaling System 7 (SS7) / Service User Part (SUP) interface is significant for signalling and control purposes, enabling smooth communication between the mobile switching centre and the signalling system.

Conclusion

PCS architecture is a technique used to develop a wireless network structure for personal communication.

It consists of components and services that communicate via interfaces and is divided into two main sections: the wireline transport network and the radio network.

Additionally, the components of PCS architecture include mobile stations, base station subsystems, network switching subsystems, and operation and support subsystems.

The architecture also includes four main types of interfaces: Um, Abis, A-interface, and SS7/SUP.