<<–2/”>a href=”https://exam.pscnotes.com/5653-2/”>h2>GSM: The Foundation of Mobile Computing
What is GSM?
GSM, which stands for Global System for Mobile Communications, is a standard for digital cellular mobile Communication. It is the most widely used mobile phone system in the world, with over 90% of the global market share. GSM was developed in Europe in the 1980s and was first launched in 1991. It has since been adopted by many countries around the world, including the United States, Canada, and Australia.
Key Features of GSM
- Digital Technology: GSM uses digital technology to transmit voice and data, which provides better Sound quality and security compared to analog systems.
- Frequency Division Multiple Access (FDMA): GSM uses FDMA to allocate different frequency bands to different users, allowing multiple users to share the same Network Resources.
- Time Division Multiple Access (TDMA): GSM also uses TDMA, which divides each frequency band into time slots, allowing multiple users to share the same frequency band by transmitting in different time slots.
- SIM Card: GSM uses a Subscriber Identity Module (SIM) card to store user information, including their phone number, contact list, and other data.
- Roaming: GSM networks allow users to roam between different networks in different countries, providing seamless connectivity.
- Short Message Service (SMS): GSM supports SMS, which allows users to send and receive text messages.
- General Packet Radio Service (GPRS): GSM networks support GPRS, which provides data connectivity for mobile devices.
- Enhanced Data Rates for GSM Evolution (EDGE): EDGE is an enhancement to GPRS that provides faster data speeds.
Evolution of GSM
GSM has evolved over the years to meet the increasing demand for faster data speeds and new features. Some of the key evolutions include:
- GSM Phase 2: Introduced in 1992, this phase added support for data Services, including SMS and GPRS.
- GSM Phase 2+: Introduced in 1997, this phase added support for EDGE, which provided faster data speeds.
- GSM Phase 3: Introduced in 2000, this phase added support for 3G networks, which provided even faster data speeds and new features like video calling.
- GSM Phase 4: Introduced in 2008, this phase added support for 4G networks, which provided even faster data speeds and new features like mobile broadband.
GSM Network Architecture
The GSM network architecture consists of several key components:
- Base Station Subsystem (BSS): The BSS is responsible for managing the communication between the mobile phone and the network. It consists of base stations, which are responsible for transmitting and receiving signals from mobile phones.
- Network Switching Subsystem (NSS): The NSS is responsible for managing the network resources, including call routing, authentication, and billing. It consists of several components, including the Mobile Switching Center (MSC), the Home Location Register (HLR), and the Authentication Center (AuC).
- Operation Support System (OSS): The OSS is responsible for managing the network operations, including network monitoring, fault management, and performance management.
GSM Network Operation
When a mobile phone makes a call, the following steps occur:
- The mobile phone sends a signal to the nearest base station.
- The base station forwards the signal to the MSC.
- The MSC routes the call to the recipient’s mobile phone.
- The recipient’s mobile phone receives the call and sends a signal back to the base station.
- The base station forwards the signal back to the MSC.
- The MSC routes the signal back to the caller’s mobile phone.
Advantages of GSM
- Wide Coverage: GSM networks have a wide coverage area, making it possible to make calls and access data from almost anywhere in the world.
- Interoperability: GSM networks are interoperable, which means that users can roam between different networks in different countries.
- Security: GSM networks use encryption to protect user data from unauthorized access.
- Cost-Effectiveness: GSM networks are relatively cost-effective, making them accessible to a wide range of users.
Disadvantages of GSM
- Limited Data Speeds: GSM networks have limited data speeds compared to newer technologies like 4G and 5G.
- Limited Bandwidth: GSM networks have limited bandwidth, which can lead to congestion during peak hours.
- Vulnerability to Interference: GSM networks are vulnerable to interference from other wireless devices.
GSM and Mobile Computing
GSM has played a crucial role in the development of mobile computing. The introduction of GPRS and EDGE enabled mobile devices to access the Internet and download data, paving the way for the development of mobile apps and services. The evolution of GSM to 3G and 4G networks has further enhanced mobile computing capabilities, enabling users to access high-speed internet, stream Videos, and download large files on their mobile devices.
Table 1: GSM Network Architecture
| Component | Description |
|---|---|
| Base Station Subsystem (BSS) | Manages communication between mobile phones and the network |
| Network Switching Subsystem (NSS) | Manages network resources, including call routing, authentication, and billing |
| Operation Support System (OSS) | Manages network operations, including network monitoring, fault management, and performance management |
Table 2: GSM Evolution
| Phase | Year | Key Features |
|---|---|---|
| GSM Phase 2 | 1992 | Introduced support for data services, including SMS and GPRS |
| GSM Phase 2+ | 1997 | Introduced support for EDGE, which provided faster data speeds |
| GSM Phase 3 | 2000 | Introduced support for 3G networks, which provided even faster data speeds and new features like video calling |
| GSM Phase 4 | 2008 | Introduced support for 4G networks, which provided even faster data speeds and new features like mobile broadband |
Frequently Asked Questions
Q: What is the difference between GSM and CDMA?
A: GSM and CDMA are two different standards for digital cellular mobile communication. GSM uses FDMA and TDMA to allocate network resources, while CDMA uses Code Division Multiple Access (CDMA) to allocate network resources. GSM is more widely used than CDMA, particularly in Europe and Asia.
Q: What is the difference between GSM and LTE?
A: GSM is a 2G technology, while LTE is a 4G technology. LTE provides much faster data speeds and improved network capacity compared to GSM.
Q: What is the future of GSM?
A: GSM is gradually being replaced by newer technologies like 4G and 5G. However, GSM networks are still widely used in many parts of the world, and they are likely to continue to be used for several years to come.
Q: How can I check if my phone is GSM or CDMA?
A: You can check the phone’s documentation or contact your mobile carrier to determine whether your phone is GSM or CDMA.
Q: What is the difference between a SIM card and a USIM card?
A: A SIM card is used in GSM networks, while a USIM card is used in UMTS (3G) networks. USIM cards have a larger memory capacity than SIM cards and support more advanced features.