Mobile telephony

Mobile Telephony In the subject Technology, the topic Mobile Telephony refers to the wireless communication system that enables voice and data transmission through mobile devices. It has revolutionized the way people connect, offering portability, instant access, and global reach.

Mobile telephony

Definition: Mobile telephony refers to wireless communication systems that allow users to make voice calls, send text messages, and access data services through portable devices (e.g., mobile phones, tablets).

Key Features of Mobile Telephony:

1. Wireless Communication: Uses radio frequencies to connect devices without physical wires.
2. Cellular Technology: Divides geographical areas into cells, each served by a base station.
3. Portability: Users can move while staying connected to the network.
4. Network Switching: Calls and data are seamlessly transferred between cells as the user moves.
5. Real-Time Access: Enables instant voice calls, messaging, and internet usage.

Examples of Mobile Telephony in Daily Life:

1. Voice Communication: Phone calls using 4G or 5G networks.
2. Messaging Services: SMS, WhatsApp, and other instant messaging platforms.
3. Internet Access: Browsing websites, streaming videos, or using social media on mobile devices.

Difference Between Mobile and Fixed Telephony

Feature	Mobile Telephony	Fixed Telephony
Connectivity	Wireless, portable	Wired, location-specific
Infrastructure	Requires base stations, MSCs, and wireless links	Requires physical cables and switching centers
Mobility	Users can move freely while connected	Restricted to the location of the phone line
Applications	Voice, SMS, internet, multimedia	Primarily voice communication

Components of a Mobile Telephony System

Mobile communication relies on the cellular network structure, where the coverage area is divided into smaller regions known as cells (Hexagonal). Each cell is served by a base station that provides the signal and communicates with the mobile devices within that cell.

Key Components of the Cellular Network:

• Cell Towers (Base Stations):
  • Each cell tower is responsible for covering a particular geographical area (cell) and facilitating communication with the mobile devices in that area.
  • Cells are connected in a grid to provide seamless coverage across large areas.
• Mobile Devices (User Equipment):
  • Mobile phones, smartphones, and other mobile communication devices that send and receive signals.
• Mobile Switching Centers (MSC):
  • The MSC is a central component that connects base stations to the core network. 
  • It works as a central hub that routes calls and data between base stations and external networks (e.g., PSTN or the internet).
  • It also manages handoffs between different base stations and handles voice and data traffic.
• Core Network:
  • The backbone of the mobile telephony system, connecting all base stations and switching centers to external networks.
• Backhaul Network:
  • Backhaul refers to the network infrastructure that connects base stations to the core network, usually through fiber optic cables or microwave links.
• Handover (Handoff)
  • Handover is the process of transferring an ongoing call or data session from one cell to another as a mobile device moves through the network. This ensures continuous service without interruption.

Modulation and Multiplexing Techniques

Modulation:

• In mobile phones, voice signals are modulated onto radio waves for transmission to the cell tower.

Types of Modulation:

• Frequency Modulation (FM): Common in analog systems.
• Quadrature Amplitude Modulation (QAM): Used in digital systems to transmit multiple bits per symbol.

Multiplexing:

• Definition: Allows multiple users to share the same frequency channel.
• Examples:
  • FDMA (Frequency Division Multiple Access): Divides the available frequency spectrum into separate channels.
  • TDMA (Time Division Multiple Access): Allocates time slots for users to share the same frequency.
  • CDMA (Code Division Multiple Access): Uses unique codes to allow multiple users to share the same frequency without interference.
  • Orthogonal Frequency Division Multiplexing (OFDM): Splits the frequency band into many smaller subcarriers, each transmitting a small portion of the data. It reduces interference and increases data rates.

Switching Techniques

Switching determines how connections are established and managed in communication networks.

• Circuit Switching:
  • How it Works: A dedicated communication path is established between two users for the duration of the call.
  • Used in: 1G (analog) and 2G (GSM) for voice calls.
  • Advantages: Reliable, constant quality during a call.
  • Disadvantages: Inefficient, as the dedicated path remains open even when no data is transmitted.

• Packet Switching:
  • How it Works: Data is divided into small packets and transmitted across the network independently. Each packet may take a different route to reach the destination, where they are reassembled.
  • Used in: 3G (HSPA), 4G (LTE), and 5G networks for internet data.
  • Advantages: More efficient, bandwidth is shared dynamically.
  • Disadvantages: Delay in transmission due to packet routing and reassembly.

Data Transmission:

• Mobile networks use packet-switching for efficient transmission of data over the internet, which breaks data into smaller packets and sends them to the destination.
• Example: When you browse the internet or stream a video on your mobile device, data is transmitted in packets from the server to your device.

Evolution of Mobile Telephony

Picture Courtesy- Telenor IoT

1G (First Generation): Analog Communication (1980s)

• Key Features:
  • Based on analog communication systems.
  • Allowed only voice communication (no SMS or data).
  • Operated on Frequency Division Multiple Access (FDMA) technology.
    • In FDMA, total available spectrum is chop up into frequency slots. Each user is allocated a unique frequency slot. During the period of the call, no other user could share the same frequency slots.
  • Large-sized phones with limited battery life.
• Technology Used:
  • Analog signals, where voice was transmitted in continuous waveforms.
  • Operated in the 800 MHz frequency band.
• Limitations:
  • Poor voice quality and high noise interference.
  • No data or messaging services.
  • Lack of security, as calls could easily be intercepted.
• Example Devices:
  • Motorola DynaTAC 8000X: The first commercially available mobile phone in 1983.
  • Weighed over 1 kg and offered just 30 minutes of talk time.
• Global Impact:
  • Enabled mobility in communication for the first time.
  • Primarily used by professionals due to high costs.

2G (Second Generation): Digital Communication (1990s)

• Key Features:
  • Marked the shift from analog to digital communication.
  • Introduction of Short Message Service (SMS) and basic data services.
  • Operated on Global System for Mobile Communication (GSM) and Code Division Multiple Access (CDMA) technologies.
• Technology Used:
  • Time Division Multiple Access (TDMA): Divided frequencies into time slots to accommodate more users.
    • TDMA: Users share a common frequency spectrum by occupying different time slots.
    • CDMA (Code Division Multiple Access): Allows multiple users to share the same frequency spectrum simultaneously by encoding each user’s information with a unique code. 
  • Operated in the 900 MHz and 1800 MHz frequency bands.
• Advantages Over 1G:
  • Improved voice clarity and less noise.
  • Enhanced security with digital encryption of calls.
  • Introduction of SIM cards, making phones more portable between networks.
• Example Devices: Nokia 1100
• Global Impact:
  • Rapid adoption due to affordability and text messaging.
  • Expanded coverage in rural and urban areas.

2.5G: Bridging the Gap to 3G

• Key Features:
  • Improved data speeds compared to 2G but not full-fledged 3G.
  • Introduced technologies like GPRS (General Packet Radio Service) and EDGE (Enhanced Data Rates for GSM Evolution).
    • GPRS: Packet-switched data transmission for internet access, working alongside GSM.
    • EDGE (in 2.75G): Enhanced modulation (8-PSK) over GPRS for higher data transfer speeds
  • Enabled access to basic internet services like browsing and emails.

3G (Third Generation): Mobile Internet Revolution (2000s)

• Key Features:
  • Focused on data transmission with speeds of up to 2 Mbps.
  • Allowed high-speed internet access, video calls, and multimedia services.
  • Operated on Universal Mobile Telecommunication System (UMTS) and Wideband CDMA (WCDMA)technologies.
    • UMTS/WCDMA: Employs CDMA (Code Division Multiple Access) for efficient spectrum use, supporting faster data rates.
• Technology Used:
  • Packet switching for efficient data transfer.
  • Operated in the 2.1 GHz frequency band.
• Advantages Over 2G:
  • Enabled seamless video calling and online streaming.
  • Introduced mobile apps and multimedia messaging services (MMS).
• Example Devices: Apple iPhone 3G.
• Global Impact:
  • Sparked the mobile app revolution, leading to services like WhatsApp and Facebook on mobile.

4G (Fourth Generation): Broadband on Mobile (2010s)

• Key Features:
  • Marked the transition to all-IP networks, offering broadband-like speeds on mobile devices.
  • Download speeds up to 1 Gbps.
  • Introduction of Voice over LTE (VoLTE) for high-definition voice calls.
• Technology Used:
  • LTE (Long-Term Evolution) and WiMAX standards.
  • Operated in the 700 MHz, 1800 MHz, and 2600 MHz frequency bands.
• Advantages Over 3G:
  • Allowed HD video streaming, online gaming, and large-scale file transfers.
  • Improved network reliability and reduced latency.
• Example Devices:
  • Samsung Galaxy S Series and iPhone 6 Series.
• India-Specific Example:
  • Reliance Jio disrupted the telecom market in 2016 by offering affordable 4G data plans, making mobile internet accessible to millions.
• Global Impact:
  • Triggered the digital revolution with cloud computing, video conferencing, and remote working solutions.

LTE: Long-Term Evolution

• LTE is a 4G wireless broadband standard designed for high-speed data transfer, focusing on low latency and high capacity.
• Based on OFDMA (Orthogonal Frequency Division Multiple Access) for downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) for uplink.
• Provides all-IP architecture, eliminating circuit-switched networks (used in 2G/3G) for voice and data.
  • Both voice (VoIP) and data are transmitted over the same IP-based infrastructure.

Key Features:

• High Data Rates: Speeds up to 300 Mbps (downlink) and 75 Mbps (uplink).
• Low Latency: <10 ms, enabling real-time applications like video conferencing and gaming.
• MIMO (Multiple Input Multiple Output): Uses multiple antennas to boost data throughput and reliability.

5G (Fifth Generation): Ultra-Connectivity (2020s)

• Key Features:
  • Ultra-high-speed internet with download speeds of up to 10 Gbps.
  • Low latency (<1 millisecond) for real-time communication.
  • Massive Device Connectivity: 5G can support up to 1 million devices per square kilometer, making it ideal for IoT networks.
  • Network Slicing: 5G enables the creation of virtual networks (slices), allowing operators to provide customized services based on specific requirements such as reliability, speed, and latency for different applications (e.g., healthcare, smart cities).

Technology Used:

• New Radio (NR): 5G introduces a new radio interface, known as New Radio (NR). 5G NR supports both Sub-6 GHz frequencies (below 6 GHz) and millimeter-wave (mmWave) frequencies (above 24 GHz), allowing much higher data transfer rates.
  • Millimeter-wave bands enable ultra-fast speeds but may have shorter range due to signal attenuation.
• Small Cells and Massive MIMO: 5G uses small cells and massive MIMO (Multiple Input Multiple Output) antennas to enhance network capacity and coverage. Small cells are low-power, short-range base stations that improve connectivity in dense urban environments. Massive MIMO uses a large number of antennas to increase the efficiency and capacity of a wireless network.
• Millimeter Waves: 5G operates in higher frequency bands, including millimeter waves (24 GHz and above), which provide much greater bandwidth than traditional cellular frequencies. These high-frequency bands allow for faster data transmission and greater capacity but have a limited range and are more susceptible to obstacles and interference.
• Millimeter-Wave Technology for higher frequency bands (24 GHz – 100 GHz).
• Advanced beamforming focus signals directly to devices, enhancing signal quality and efficiency .
• Uses OFDM (Orthogonal Frequency Division Multiplexing) as the base waveform for both uplink and downlink, allowing efficient use of spectrum and better handling of interference.
• Dynamic Spectrum Sharing (DSS): Enables efficient use of existing 4G and 5G spectrum, allowing both technologies to share the same frequency band → facilitating a smoother transition between technologies.
• Advantages Over 4G:
  • Enables applications like autonomous vehicles, remote surgeries, and smart cities.
  • Enhances industrial automation and augmented reality (AR)/virtual reality (VR).
• Example Devices:
  • Samsung Galaxy S23 Ultra and iPhone 15 Pro are 5G-enabled devices.
• India-Specific Example:
  • 5G rollout by Airtel and Reliance Jio in 2022 has started transforming urban and rural connectivity.
• Global Impact:
  • Transforming industries like healthcare, manufacturing, and education through ultra-reliable communication systems.

Future Evolution: Beyond 5G (6G)

• Expected launch: 2030s ;  Speeds up to 1 Tbps (terabits per second). 
• Integration of AI for intelligent communication systems.
• Use cases: Advanced holographic communication, space-based internet, and human-machine interfaces.

Bharat 6G Vision: released in 2023

• Launched to position India as a global leader in 6G technology by 2030, this initiative includes the establishment of the Bharat 6G Alliance (B6GA), which brings together industry stakeholders, academia, and international partners to collaborate on 6G development.

Patent Goals: 

The government has an aspiration that Indian entities should own at least 10% of overall 6G patents by 2030, but the country faces significant challenges in pursuing 6G leadership, particularly in infrastructure readiness and securing adequate funding for research and development.

Feature	5G	6G
Speed	Up to 20 Gbps(theoretical)	Expected 100 Gbps to 1 Tbps
Latency	As low as 1 millisecond	Targeting 1 microsecond
Spectrum Usage	Sub-6 GHz and above 24.25 GHz	30 GHz to 3 THz
Technological Innovations	Enhanced mobile broadband capabilities	Holographic communication, AI-driven management, seamless IoT connectivity
Energy Efficiency	Moderate efficiency improvements	Anticipated to be significantly more energy-efficient
Applications	Improved gaming, autonomous driving	Advanced telemedicine, immersive VR/AR experiences, Industry 4.0 applications

Generation	Key Features	Technology Used	Speed	Global Impact
1G (1980s)	Analog voice communication, large phones, no SMS or data	FDMA, analog signals (800 MHz band)	~2.4 Kbps	Enabled mobile communication but had poor voice quality, no data services, and high costs.
2G (1990s)	Digital voice and SMS, portable phones	GSM, CDMA, TDMA (900/1800 MHz bands)	~64 Kbps	Improved voice clarity, SMS, enhanced security – Made mobile phones affordable and widespread, with rapid adoption in rural and urban areas.
2.5G (Late 1990s – Early 2000s)	Improved data speeds, basic internet browsing	GPRS, EDGE	~100-200 Kbps	Bridged the gap between 2G and 3G, enabling mobile email and basic browsing.
3G (2000s)	High-speed internet, video calls, multimedia services	UMTS, WCDMA, packet switching (2.1 GHz band)	~2 Mbps	Seamless video calling, streaming, mobile apps -Sparked the mobile app revolution, enabling services like WhatsApp and Facebook on mobile.
4G (2010s)	Broadband speeds, VoLTE, HD streaming	LTE, WiMAX (700/1800/2600 MHz bands)	~1 Gbps	HD video, gaming, large-scale file transfers -Triggered the digital revolution, enabling cloud computing, video conferencing, and remote work.
5G (2020s)	Ultra-high-speed, low latency, IoT ecosystems	Millimeter-Wave, beamforming, MIMO (24-100 GHz)	~10 Gbps	Autonomous vehicles, AR/VR, smart cities -Transforming industries like healthcare and manufacturing, with widespread urban and rural connectivity advancements.
Beyond 5G (6G) (Expected in 2030s)	Expected AI integration, holographic communication	TBD	~1 Tbps	Space-based internet, advanced human-machine interfaces -Aiming for unprecedented speeds, revolutionizing communication with intelligent systems and new use cases like space-based networks.

The 5G spectrum allocation in India

Total Spectrum Available

• Total Spectrum Offered: Approximately 72,097.85 MHz across various bands.
• Validity Period: The spectrum is allocated for a duration of 20 years.

Frequency Bands Allocated: The spectrum auction covered multiple frequency bands categorized as low, mid, and high:

• Low Band: 600 MHz, 700 MHz, 800 MHz, 900 MHz, 1800 MHz, 2100 MHz, 2300 MHz
• Mid Band: 3300 MHz
• High Band: 26 GHz

First Major Auction (August 2022)

• Total Bids: The auction generated bids totaling ₹1.5 lakh crore (approximately US$17.97 billion), securing 71% of the available spectrum.
  • Reliance Jio secured 24.74 GHz of spectrum, spending ₹88,078 crore.
  • Bharti Airtel acquired 19.867 GHz of spectrum, with a bid of ₹43,084 crore.
  • Adani Group: Acquired spectrum in the 26 GHz band for a private network.

Second Auction (June 2024)

• Total Bids: The auction raised approximately ₹11,340 crore (US$1.35 billion), much lower than the expected ₹96,000 crore (US$11.3 billion) valuation.  → only about 12% of the targeted revenue
• Spectrum Offered: A total of 10,523 MHz was available
• Top Bidders:
  • Bharti Airtel: Acquired airwaves worth ₹6,856.76 crore (97 MHz total).
  • Vodafone Idea: Spent ₹3,510 crore (50 MHz total).
  • Reliance Jio: Bid ₹973.62 crore for additional spectrum.

Telecommunications Act, 2023

Overview

• Enacted: December 25, 2023
• Replaces: Indian Telegraph Act, 1885 & Indian Wireless Telegraphy Act, 1933
• Objective: Modernize and regulate telecommunication services in India.

Key Provisions

• Regulation of OTT Services:
  • The Act extends its regulatory framework to include over-the-top (OTT) services, bringing them under similar regulations as traditional telecom services.
• Government Powers:
  • Authority to suspend or prohibit telecom equipment for national security.
  • Can manage or suspend telecom services in the interest of national security.
• Spectrum Allocation:
  • Introduces auction-based spectrum allocation, with a focus on satellite broadband to improve rural connectivity.
• Right of Way (RoW):
  • Establishes framework for laying telecom infrastructure on public/private property.
• Consumer Protection:
  • Protects consumer rights and ensures data privacy.
  • Encourages telecom sector research & development.
• Interception and Surveillance:
  • Permits communication interception for state security and public order.

Reactions

• Positive Aspects:
  • Better regulation of OTT services, providing legal clarity to digital services.
  • Support for the adoption of modern technologies in the telecommunications sector.
  • Expansion of telecom services in rural areas.
• Criticism:
  • Excessive government authority may pose a threat to privacy and freedom of expression.
  • Lack of transparency in the drafting process.
  • Replacing the Universal Service Obligation Fund (USOF) with the “Digital Bharat Nidhi” may impact rural telecom services.