TelecomStudy18

Multimedia Broadcast Multicast Service, MBMS A new service introduced in 3GPP Release 6 specifications is Multimedia Broadcast Multicast Service (MBMS). There are two high level modes of operation in MBMS, as given   1.        Broadcast mode, which allows sending audio and video. The already existing Cell Broadcast Service (CBS) is intended for messaging only. The broadcast mode is expected to be a service without charging and there are no specific activation requirements for this mode. 2.          Multicast mode allows sending multimedia data for the end users that are part of a multicast subscription group. End users need to monitor service announcements regarding service availability, and then they can join the currently active service. From the network point of view, the same content can be provided in a point-to-point fashion if there are not enough users to justify the high power transmission. A ...

Push-to-talk over cellular (PoC) service is instant in the sense that the voice connection is established by simply pushing a single button and the receiving user hears the speech without even having to answer the call. While ordinary voice is bi-directional, the PoC service is a one directional service. The basic PoC application may hence be described as a walkie-talkie application over the packet switched domain of the cellular network. In addition to the basic voice communication functionality, the PoC application provides the end user with complementary features like, for example:       ·          Ad hoc and predefined communication groups; ·          Access control so that a user may define who is allowed to make calls to him/her; ·          ‘Do-not-disturb’ in case immediate reception of audio is not desirable. With ordina...

Main differences between the third and second generation air interfaces are described. GSM and IS-95 (the standard for cdmaOne systems) are the second generation air interfaces considered here. Other second generation air interfaces are PDC in Japan and US-TDMA mainly in the Americas; these are based on TDMA (time division multiple access) and have more similarities with GSM than with IS-95. The second generation systems were built mainly to provide speech services in macro cells. To understand the background to the differences between second and third generation systems, we need to look at the new requirements of the third generation systems which are listed below:        ·          Bit rates up to 2 Mbps; ·          Variable bit rate to offer bandwidth on demand; ·          Multiplexing of services with different quality requir...

Link budget planning is part of the network planning process, which helps to dimension the required coverage, capacity and quality of service requirement in the network. UMTS WCDMA macro cell coverage is uplink limited, because mobiles power level is limited to (voice terminal 125mW). Downlink direction limits the available capacity of the cell, as BTS transmission power (typically 20-40W) has to be divided to all users. In a network environment both coverage and capacity are interlinked by interference. So by improving one side of the equation would decrease the other side. System is loosely balanced by design. The object of the link budget design is to calculate maximum cell size under given criteria: Type of service (data type and speed) Type of environment (terrain, building penetration) Behavior and type of mobile (speed, max power level) System configuration (BTS antennas, BTS power, cable losses, handover gain) Required coverage probability

Hybrid automatic repeat-request(HARQ) :Data and voice blocks are transmitted in 10 ms time-intervals called frames. At each frame and for each transmission the SIR is evaluated and used to derive the Block Error Rate (BLER).  Each block is then considered correct or erroneous according to a random experiment based on the BLER. For the packet switched traffic only, an ideal ARQ procedure is adopted, i.e., the transmitted block is kept in the transmitting queue in case of error and is cancelled otherwise Cell breathing is the constant change of the range of the geographical area covered by a cellular telephone transmitter based on the amount of traffic currently using that transmitter. When a cell becomes heavily loaded, it shrinks.

5 codes and qpsk= 1.8mbps; 5 codes and 16 qam= 3.6 mbps; 10 codes and 16 qam= 7.2 mbps; 15 codes and 16 qam= 14.4; 15 codes and 64 qam= 21.1mbps; 15 codes and 16 qam(mimo)=28mbps; 16 codes and 64 qam(mimo)=42.2mbps

SIB1 : NAS Information. UE Timers and counters to be used in RRC Idle & Connected State, SIB2 : List of URA Identities SIB3 : Parameters for Cell Selection and Reselection SIB4 : Same as SIB3 but used in Connected State SIB5 : Configuration parameters of common physical channels in a cell. PCH and PICH Info (CPCH) SIB6 : Configuration of Common and Shared physical channel SIB7 : Contains fast changing UL interface params and dynamic. As this is changes often so controlled by timer SIB8 : Used in FDD . Static CPCH info of cell. Used in Connected mode only SIB9 : CPCH info. As it changed often, controlled by timers connected mode only. SIB10 : DRAC Procedure, used when CELL_DCH controlled by timer SIB11 : Measurement control information to be used in CELL SIB12 : Same as SIB11 but used in connected mode only SIB13 : For ANSI-41 . It also has 4 associated SIBS 13.1 to 13.4. Reference to subblocks. Used when System is ANSI-41. SIB14 : Parameters for common and dedicat...

compModeAdm: Absolute admission limit for the number of radio links in compressed mode in a cell. dlCodeAdm: Parameter that defines in percentage the absolute admission limit for DL code usage pwrAdm: Parameter that defines in percentage the absolute admission limit for DL power utilization. sf8Adm: Defines the absolute admission limit for the number of RLs with SF=8 (PS384) in DL. sf16Adm: Defines the absolute admission limit for the number of RLs with SF=16 (PS128 RAB) in DL. sf32Adm: Defines the absolute admission limit for the number of RLs with SF=32 (PS64) in DL. sf4AdmUl: Absolute admission limit for the number of RLs with SF=4 in UL (PS384/HS) sf8AdmUl: Defines the absolute admission limit for the number of RLs with SF=8 in UL. sf16AdmUL: Parameter that defines absolute admission limit for the number of RLs with SF=16 in UL.

Network Optimization process involves the following activities: FIRST SET THE CRITERION ( GOAL) OF OPTIMIZATION PROCESS BASELINE & TARGET KPI’s. DELIVERABLES CONDUCTING A BASELINE PHYSICAL AUDIT REMOVING ALL SERVICE AFFECTING ALARMS IDENTIFYING POOR COVERAGE AREAS IDENTIFYING CAPACITY CONSTRAINTS & OVERUTILIZED CELLS VARIOUS KPIs with Root-Cause-Analysis of problems. Frequency Plan (BCCH & TCH) Neighbor plan CONDUCTING A GSM SYSTEM PARAMETERS AUDIT Deliverables of an Optimization activity: Baseline Drive test comparison with post implementation results. Statistical comparison of baseline & improved network. Parameter Audit report. Physical parameter inconsistencies. Frequency & neighbor plan inconsistencies Recommendations for Coverage Capacity Physical Optimization Location Area Optimization.

Paging process in WCMDA or HSDPA system is called WCMDA Paging. The Paging Channel (PCH) is a downlink transport channel. The PCH is always transmitted over the entire cell. The transmission of the PCH is associated with the transmission of physical-layer generated Paging Indicators, to support efficient sleep-mode procedures. Paging Channel selection System information Block Type 5  (SIB 5)  defines common channels to be employed in Idle mode. The UE may use Discontinuous Reception (DRX) in idle mode in order to reduce power consumption. When DRX is used the UE needs only to monitor one Page Indicator, PI, in one Paging Occasion per DRX cycle. The Paging Indicator Channel (PICH) is a fixed rate (SF=256) physical channel used to carry the paging indicators. Paging Procedure: Basically two types of Paging Procedures in WCMDA Paging. 1) Idle Mode Paging 2) Dedicated Mode Paging Idle mode paging  is used when UE is in idle mode so we can say ...

1.         What is the WCDMA technology? 2.         What is the different between WCDMA & GSM? 3.         What is the different between CDMA & WCDMA? 4.         What is architecture & Interface of WCDMA? 5.         What are the channel concepts of WCDMA Network? 6.         What are the Logical, transport & physical channel in WCDMA? 7.         What is the channel mapping in WCDMA? 8.         What is the cell search procedure? 9.         What are the RRC and what are the RRC states? 10.       What is location registration? 11.       What ...

WCDMA RAN WCDMA RAN is a part of the 3rd generation (3G) mobile system, and comprises: OSS-RC RNC RANAG RBS WCDMA RAN has interfaces towards the Core Network (CN), and towards the external Network Management Systems (NMS). WCDMA RAN provides Radio Access Bearers (RAB) between the CN and the subscriber's User Equipment (UE) for speech, data, and multimedia services. The Network Elements (NEs) RNC, RANAG, and RBS provide and manage the data links between WCDMA RAN and the UE. The links between the NEs in WCDMA RAN carry the user data within WCDMA RAN. These physical links are also used to carry O&M data. See figure for an overview of WCDMA RAN. 

FADING in Telecomunication •           The communication between the base station and mobile station in mobile systems is mostly non-LOS. •           The LOS path between the transmitter and the receiver is affected by terrain and obstructed by buildings and other objects. •           The mobile station is also moving in different directions at different speeds. •           The RF signal from the transmitter is scattered by reflection and diffraction and reaches the receiver through many non-LOS paths. This non-LOS path causes long-term and short term fluctuations in the form of log-normal fading and rayleigh and rician fading, which degrades the performance of the RF channel LONG TERM FADING •           Terrain configuration & man made enviro...

The 2G/3G inter-RAT handover involves the handover from GSM to UMTS and the handover from UMTS to GSM. The handover is controlled mainly by the network. For MSs in dedicated mode, inter-RAT handovers can be performed, including the emergency handover, better cell handover, inter-RAT load handover, and inter-RAT service handover. Inter-RAT Handover from UMTS to GSM MSs in dedicated mode can be handed over from a UMTS cell to a GSM cell. The handover decision and handover procedure are controlled by the RNC. The BSS considers the incoming handover from UMTS to GSM as a common inter-BSC handover.  The parameter Inter-RAT In BSC Handover Enable determines whether inter-RAT handover from UMTS to GSM is enabled. If Inter-RAT In BSC Handover Enable is set to No , the BSS rejects all the requests for the handover from UMTS to GSM. Inter-RAT Handover from GSM to UMTS The parameter Inter-RAT In BSC Handover Enable determines whether the inter-RAT handover from GSM to UMTS is...

High-Speed Downlink Packet Access   ( HSDPA ) is an enhanced   3G   (third-generation)   mobile telephony   communications protocol   in the   High-Speed Packet Access   (HSPA) family, also dubbed 3.5G, 3G+, or Turbo 3G, which allows networks based on   Universal Mobile Telecommunications System   (UMTS) to have higher data-transfer speeds and capacity. As of 2013  HSDPA deployments can support down-link speeds of up to 42.3  Mbit /s.   HSPA+   offers further speed increases, providing speeds of up to 337.5 Mbit/s with Release 11 of the   3GPP   standards Capacity • It is the maximum throughput that the RBS can deliver to one cell. The capacity is shared by all HSDPA users. System Capacity • It is the average capacity per cell for a cluster of cells. For system capacity calculation it is assumed that the load is homogenously distributed and HSDPA is deployed in all cells. Dedicated Cha...