CS702(C) Unit 4 Mobile Transport Layer and GSM study material for RGPV CSE 7th Semester. Learn mobile transport layer, unsuitability of traditional TCP, I-TCP, S-TCP, M-TCP, wireless cellular networks, GSM services, GSM architecture, localization, calling, handover and roaming.
Unit 4 explains why traditional TCP does not perform well in mobile and wireless environments. It covers mobile TCP improvements such as I-TCP, S-TCP and M-TCP, along with cellular network concepts and GSM architecture including localization, handover and roaming.
Understand why traditional TCP is unsuitable for mobile and wireless networks.
Learn different TCP approaches designed for mobility and wireless communication.
Study GSM services, system architecture, localization, calling, handover and roaming.
Complete syllabus-based topics of Wireless & Mobile Computing Unit 4.
Mobile transport layer provides end-to-end communication support for mobile users over wireless networks.
Traditional TCP assumes packet loss mainly occurs due to congestion, but in wireless networks losses may occur due to mobility, handoff and signal errors.
Traditional TCP performs poorly in wireless networks because it cannot distinguish between congestion loss and wireless transmission loss.
Indirect TCP splits the TCP connection into wired and wireless parts to improve performance in mobile networks.
I-TCP improves wireless link performance, hides wireless errors from the fixed network and provides better local recovery.
I-TCP breaks end-to-end TCP semantics and requires extra support at the base station.
Snooping TCP monitors TCP packets at the base station and locally retransmits lost packets without breaking end-to-end connection.
Mobile TCP separates congestion control from wireless loss handling and tries to preserve TCP end-to-end semantics.
Wireless cellular networks divide a geographical area into cells, each served by a base station.
A cellular system uses frequency reuse, base stations and switching centers to provide mobile communication.
Cellular networks cover large areas with mobility support, while WLANs provide short-range local wireless access.
GSM provides telephony services, bearer services and supplementary services for mobile users.
GSM architecture consists of Mobile Station, Base Station Subsystem, Network Switching Subsystem and Operation Support Subsystem.
Mobile Station includes the mobile device and SIM card used by the subscriber to access GSM services.
BSS includes BTS and BSC. It handles radio communication between mobile station and network.
NSS handles call switching, mobility management, authentication and subscriber database management.
Localization identifies the current location area of a mobile user so calls and messages can be routed correctly.
GSM call setup involves locating the subscriber, allocating radio channels and establishing connection through switching centers.
Handover transfers an ongoing call or session from one cell or base station to another without disconnecting.
Roaming allows mobile users to access network services outside their home network coverage area.
Traditional TCP Problem: Wireless packet loss ko congestion loss samajh leta hai.
I-TCP: TCP connection ko wired aur wireless parts me split karta hai.
S-TCP: Base station par packet snooping and local retransmission karta hai.
M-TCP: End-to-end semantics preserve karne ki koshish karta hai.
GSM: Mobile communication standard with MS, BSS, NSS and OSS.
Handover: Active call ko ek cell se dusre cell me transfer karna.
Roaming: Home network ke bahar service use karna.
| Topic | Expected Frequency | Importance |
|---|---|---|
| Unsuitability of Traditional TCP | Very High | ⭐⭐⭐⭐⭐ |
| I-TCP | Very High | ⭐⭐⭐⭐⭐ |
| S-TCP | High | ⭐⭐⭐⭐ |
| M-TCP | High | ⭐⭐⭐⭐ |
| Cellular Networks | High | ⭐⭐⭐⭐ |
| GSM Services | High | ⭐⭐⭐⭐ |
| GSM Architecture | Very High | ⭐⭐⭐⭐⭐ |
| Localization and Calling | High | ⭐⭐⭐⭐ |
| Handover | Very High | ⭐⭐⭐⭐⭐ |
| Roaming | High | ⭐⭐⭐⭐ |
Traditional TCP assumes packet loss is due to congestion, but wireless networks can lose packets due to mobility and signal errors.
I-TCP splits TCP connection into wired and wireless parts to improve mobile network performance.
S-TCP monitors packets at the base station and performs local retransmission for wireless losses.
GSM is a cellular mobile communication standard used for voice, data and supplementary services.
Handover transfers an ongoing call or session from one cell to another without interruption.
Roaming allows a mobile user to use services outside the home network area.