The presentation covered computer networks and mobility management in cellular networks. It discussed IP addressing, routing to mobile nodes, call routing to mobile users, handoffs in GSM networks, and the components of GSM architecture including the mobile station, base station subsystem, network switching subsystem, operation support subsystem, home location register, visitor location register, equipment identity register, authentication center, and SMS serving center. Diagrams were shown of the 802.11 frame, soft handoff process in CDMA networks, and basic components of a GSM network.

1. Presentation on
Computer Networks

2. Group Members
Md Din-Islam 131-15-2243
Palash Das 133-15-3020

3. The 802.11 Mac Protocol

5. The 802.11 Frame

6. Mobility Management
Mobility management is one of the major functions of a GSM or
a UMTS network that allows mobile phones to work. The aim of
mobility management is to track where the subscribers are,
allowing calls, SMS and other mobile phone services to be delivered
to them.

8. Addressing
• An IP address is a unique numerical value that is used to identify
a computer on a network.
• There are two kinds of IP addresses:
- Public
- Private

10. RoutingTo A Mobile Node

11. Call Routing To Mobile User

12. Handoffs in GSM

13. This figure shows the basic soft handoff process that occurs in the
IS-95 CDMA system. In this example, the mobile device has
measured the signal strength of the pilot channel from a nearby
cell site. Using this information, it is determined that the adjacent
cell site is a candidate for the soft handoff process and that is
should simultaneously communicate with the mobile device and
the soft handoff process begins. During the soft handoff process,
information from the mobile device is simultaneously received by
both cell sites and the information frames that have the highest
quality (least errors) can be selected.

14. GSM architecture

15. The Mobile Station (MS)
The Base Station Subsystem (BSS)
The Network Switching Subsystem (NSS)
The Operation Support Subsystem (OSS)
Home Location Register (HLR)
Visitor Location Register (VLR)
Equipment Identity Register (EIR)
Authentication Center (AuC)
SMS Serving Center (SMS SC)
Gateway MSC (GMSC)
Chargeback Center (CBC)
Transcoder and Adaptation Unit (TRAU)
The GSM network can be broadly divided into: