TelecomStudy18

The main interfaces in LTE are Uu, S1-MME, X2, S1-U, S11 and S5. LTE Uu: - This is the air interface between UE and eNB. LTE layer 1 is dealt with later. RRC is the protocol that is used for communication between UE and eNB. Above RRC there is a NAS layer in UE. This NAS layer terminates at MME and eNB shall silently pass the NAS messages to MME. LTE S1-MME: - eNB and MME communicate using this IP interface. S1-AP is application layer interface. The transport protocols used here is SCTP. (Stream control transmission protocol) LTE X2: - This interface is used by a eNB to communicate to other eNB. This again is a IP interface with SCTP as transport. X2-AP is the application protocol used by eNB’s to communicate. LTE S11: - An IP interface between MME and SGW! GTPv2 is the protocols used at the application layer. GTPv2 runs on UDP transport. This interface must and should run GTPv2. LTE S5: - This is the interface between SGW and PGW. This again is an IP int...

After cell selection UE performs measurement and carry out cell reselection of new candidate cell. This is based on certain criterion. Reselection process involves 2 steps 1.     Measurements Condition:   Specifies when to start measuring neighboring cells. Once condition is met UE measures the RSRP level of the E-UTRA cells on the current frequency and any inter-frequency and inter-RAT frequency carriers. 2.      Reselection Condition: Specifies reselection criteria for candidate cell. There are two different mechanisms for cell reselection:  Legacy Based Priority Based Cell reselection can be either Legacy or Priority based. Legacy Based   This is classical Ranking based system and is applied to intra-frequency reselection. • It is also applied to inter frequencies which are equally prioritized. • UE applies cell ranking R criterion on serving cell and neighboring cell. Priority Based Priority values in t...

After cell selection UE performs measurement and carry out cell reselection of new candidate cell. This is based on certain criterion. Reselection process involves 2 steps 1.     Measurements Condition:   Specifies when to start measuring neighboring cells. Once condition is met UE measures the RSRP level of the E-UTRA cells on the current frequency and any inter-frequency and inter-RAT frequency carriers. 2.      Reselection Condition: Specifies reselection criteria for candidate cell. There are two different mechanisms for cell reselection:  Legacy Based Priority Based Cell reselection can be either Legacy or Priority based. Legacy Based   This is classical Ranking based system and is applied to intra-frequency reselection. • It is also applied to inter frequencies which are equally prioritized. • UE applies cell ranking R criterion on serving cell and neighboring cell. Priority Based Priority values in t...

Once a cell meets all requirements, Criterion S is considered for cell selection. Srxlev = [Qrxlevmeas – (Qrxlevmin + Qrxlevminoffset) – Pcompensation] > 0 Where   Pcompensation = [max (PEMAX – PUMAX , 0)] Example: (Ignoring Offset and Pcompensation) Srxlev = (Qrxlevmeas –Qrxlevmin) => -105 – (-120) = 15 db > 0 Parameter Parameter Description QrxLevmeas Measured RSRP value by UE (dBm) Qrxlevmin Required minimum RSRP level in the cell (dBm) Qrxlevminoffset Offset to Qrxlevmin PUMAX Maximum UE power according to its class PEMAX Maximum UE power to be used in a cell. Ericsson equivalent is pMaxServingCell

arfcnValueUtranDl   : Indicates the ARFCN applicable for a downlink UTRA carrier frequency,  cellReselectionPriority  : The absolute priority of the carrier frequency used by the cell reselection procedure. Default Value :7 ellReselectionPriority : The absolute priority of the concerned carrier frequency, as used by the cell reselection procedure.  Default Value :6 pMaxUtra : The maximum allowed transmission power on the (uplink) carrier frequency.  Default Value :33 sNonIntraSearch : Threshold for inter-frequency and inter-RAT measurements on frequencies of equal or lower priority.  Default Value :0 threshServingLow Threshold for the signal strength of the serving cell, below which the UE performs cell reselection towards a lower priority inter-frequency or inter-RAT frequency.  Default Value :0 threshXHigh : Specifies the threshold used by the UE when reselecting towards the higher priority frequency X than current ser...

The latest revision of the LTE standard defines bands of operation, including both paired and unpaired spectrum. 1-32 bands are for paired (FDD) operation, while bands 33-40 are for unpaired (TDD) operation Paired (FDD) and Unpaired (TDD) Operating Bands for LTE with Uplink & Downlink Frequency 

Maxico's America Movil is launching a takeover bid for the Telekom Austria Group with secure an agreement with the Austrian government's own holding company IAG. America Movil and ÖIAG have initially signed a shareholders’ agreement to effectively pool their stakes in the telecoms company into a single syndicate. America Movil already owns 26.4% of the company, while the government owns 28.4% of the telco. Now that the agreement, which had been expected, has been signed, the two companies jointly control more than 30% of the shares and are required by Austrian stock market rules to launch a takeover bid for the company. Subject to the closing of the takeover bid, the two shareholders will also pump an additional EUR1 billion into the company to help fund network upgrades. America Movil will take over management of the company, although it is expected that the Austrian government would, through ÖIAG remain the larger of the two shareholders. ÖIAG also has the right...

Definition: Signaling System 7 (SS7) is an architecture for  performing out-of-band signaling in support of the call-establishment, billing, routing, and information-exchange functions of the public switched telephone network (PSTN). It identifies functions to be performed by a signaling system network and a protocol to enable their performance. What is Signaling? Signaling refers to the exchange of information between call components required to provide and maintain service.

Long code  in CDMA is a  chip  sequence which is 2 40  chips long, which repeats every 41.4 days. Its primary purpose is to assist in spreading the signal, to make spread spectrum work more efficiently. The Long code used on the  reverse link  is usually modified using the phone's  ESN  when in a call. See  Long Code Mask .

Download the WCDMA Basic document    Click here to Download 

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...

(E)GPRS Network Infrastructure How to calculate what •           No. of EGPRS resources used in 1 sector * No. of sectors : 2 x 3 •            No. of time slot/sector * no of time slot used for EDAP :- 2 * 3 = 6 •           So total time slots per site 6 + 6 = 12 •           1 NSEI support 256 time slot with upgrade % as 10 so total no of time slots which can be equipped is 256 - 10% of 256 = 230.4 ~ 230 •           So no. of sites per NSEI is 230/12 = 19.16 ~ 19 •           So no NSEI required / BSC :  100 / 19 = 5.2 +1 (for future use) ~ 6 •           2 NSEI supports 1 BCSU so no. of PCU required : 6/2 = 3 •    ...