Dr.Mukesh Kumar

Quality of Service Network Services are considered end-to-end, this means from a Terminal Equipment (TE) to another TE. An End-to-End Service may have a certain Quality of Service (QoS) which is provided for the user of a network service. It is the user that decides whether he is satisfied with the provided QoS or not. To realise a certain network QoS a Bearer Service with clearly defined characteristics and functionality is to be set up from the source to the destination of a service. A bearer service includes all aspects to enable the provision of a contracted QoS. These aspects are among others the control signalling, user plane transport and QoS management functionality. A UMTS bearer service layered architecture is depicted below, each bearer service on a specific layer offers it's individual services using services provided by the layers below. QoS Architecture There are four different QoS classes: conversational class streaming

UMTS Security The security functions of UMTS are based on what was implemented in GSM. Some of the security functions have been added and some existing have been improved. Encryption algorithm is stronger and included in base station (NODE-B) to radio network controller (RNC) interface , the application of authentication algorithms is stricter and subscriber confidentially is tighter. The main security elements that are from GSM: Authentication of subscribers Subscriber identity confidentially Subscriber Identity Module (SIM) to be removable from terminal hardware Radio interface encryption Additional UMTS security features: Security against using false base stations with mutual authentication Encryption extended from air interface only to include Node-B to RNC connection Security data in the network will be protected in data storages and while transmitting ciphering keys and authentication data in the system. Mechanism for upgrading security f

UMTS Handover There are following categories of handover (also referred to as handoff): Hard Handover Hard handover means that all the old radio links in the UE are removed before the new radio links are established. Hard handover can be seamless or non-seamless. Seamless hard handover means that the handover is not perceptible to the user. In practice a handover that requires a change of the carrier frequency (inter-frequency handover) is always performed as hard handover. Soft Handover Soft handover means that the radio links are added and removed in a way that the UE always keeps at least one radio link to the UTRAN. Soft handover is performed by means of macro diversity, which refers to the condition that several radio links are active at the same time. Normally soft handover can be used when cells operated on the same frequency are changed. Softer handover Softer handover is a special case of soft handover where the radio links that are added and removed bel

Universal Mobile Telecommunications System (UMTS) is the European standard for 3G mobile communication systems which provide an enhanced range of multimedia services. It has evolved from its basic format through developments such as HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access) to provide very high bandwidth capabilities to support the next generation of telecommunication services. UMTS supports up to 1920 kbit/s data transfer rates (and not 2 Mbit/s as frequently seen), although at the moment users in the real networks can expect performance up to 384 kbit/s - in Japan upgrades to 3 Mbit/s are in preparation. However, this is still much greater than the 14.4 kbit/s of a single GSM error-corrected circuit switched data channel or multiple 14.4 kbit/s channels in HSCSD , and - in competition to other network technologies such as CDMA-2000, PHS or wLAN - offers access to the World Wide Web and other data se

Installation steps of NS2.29 on Ubuntu 10.04 and mannasim Step 1: Download download the ns2 copy from internet or put this command into terminal. 1] go to terminal and type wget http://nchc.dl.sourceforge.net/sourceforge/nsnam/ns-allinone-2.29.3.tar.gz 2] u can download it from here. Step 2: Extract extract the tar file in home directory i.e. /home/username OR try this in terminal tar -xzvf ns-allinone-2.29.3tar.gz Step 3 : Install just type following commands cd ns-allinone-2.34 sudo apt-get install \ libx11-dev libxmu-dev libxmu-headers libxt-dev libtool g++-4.1 Edit some 'Makefile.in' : otcl-1.11/, line 7 : CC = gcc-4.1 tclcl-1.17/, line 40 : CC = gcc-4.1 tclcl-1.17/, line 41 : CPP = g++-4.1 ns-2.29/ , line 36 : CC = gcc-4.1 ns-2.29/ , line 37 : CPP = g++-4.1 nam-1.11/, line 44 : CC = gcc-4.1 nam-1.11/, line 45 : CPP = g++-4.1 Do 'make clean' in otcl-1.11/ and next delete the 'Makefile'. Now ./install will work. Edit some paths =

Physical layer is responsible for transmission of bits from one node to the next node. Physical layer of OSI model Physical layer is responsible for following:- Physical layer is responsible for providing the interface between the device on which we are working and the transmission medium which we are using for data transfer. Physical layer is responsible for representation of bits i.e. 0 and 1 in the form of signals. The bits 0 and 1 can not transfer though the physical medium which we are using. There is a need to convert these bits into the form of signal so that can be transferred. Physical layer also define the data rate also i.e. number of bits transferred per second. Physical layer is also responsible for Synchronization of bits at the bit level means to transfer the data clock pulse of the sender and receiver must be same. Physical layer is responsible for line configuration. The line configuration will decide that whether there is a dedicated line