TelecomStudy18

The Double BA Lists feature is defined per cell. This means that it is possible to have double lists in one cell and a single list in another cell. A single list corresponds to having the same list in idle mode and in active mode. The Absolute Radio Frequency Channel Numbers (ARFCNs) to be measured on by an MS in a cell shall be included in the BA list and they are defined by the parameter MBCCHNO . Only ARFCNs for the neighboring cells BCCH frequencies shall be defined (serving cells BCCH frequency can also be included if separate idle mode and active mode BA lists are used). With the parameter LISTTYPE it is possible to determine whether the list is for idle mode or active mode, or both. Basically up to 32 measurement frequencies can be defined in the BA list. If UTRAN neighbors are registered in the cell, then the maximum number of frequencies in the BA list is 31. The following restrictions will apply according to the global system type and the list type. Note that if the list t...

The DHA feature optimizes the usage of capacity when the cell load is high, whilst offering the best possible speech quality when the cell load is low. This is achieved by allocating FR or HR TCHs in accordance with the cell load, at the time when a new TCH shall be selected due to assignment and most types of handovers. At high cell load HR TCHs have precedence and at low cell load FR TCHs have precedence. The feature is invoked if the parameter DHA is ON.   The parameter is set on cell level. The feature is not invoked at immediate assignment if using a TCH. Then it is the setting of the parameter CHAP that controls whether FR and/or HR may be used To trigger the functionality it must also be checked that the DL signal strength measured by the MS is not too low. If the signal strength is below DHASSTHRASS (if during assignment) or DHASSTHRHO (if during handover) then dynamic HR allocation evaluation will not be performed. This signal strength check can be activated a...

The Log-normal fade margin is incorporated in to the link budget calculation to ensure coverage reliability, and there are three environmental cases to consider: · Outdoor fade margin · Indoor fade margin · In-vehicle fade margin Outdoor Fade Margin The outdoor standard deviation α 0 , depends on the terrain: dense urban, urban, or suburban and may change very slightly with frequency. The outdoor standard deviation, α 0 , ranges from 5 dB (rural) to 12 dB (dense urban) with a typical value of 8 dB (suburban) Radio Wave Propagation A Indoor Fade Margin If an MS is inside a building, the received signal is attenuated as it passes through the exterior of the building. Building penetration loss, L bp is subject to random variation. We denote the standard deviation of the building penetration loss as α bp . The standard deviation, α , used to compute the indoor fade margin accounts for the outdoor environment, as well as the random variation of the building penetration...

TBFDCDLCAP :  Number of downlink TBFs where the MS is capable of using dual carriers. TRAFDCDLTBF :   Number of downlink TBFs, in EGPRS mode, reserved on dual carriers. MAXDCTSDL :  Maximum possible number of time slots reservable for MSs on downlink TBFs in EGPRS mode, reserved on dual carriers. MUTILDCDL :  Sum of percentage shares of reserved time slots for all EGPRS mode downlink TBFs reserved on dual carriers related to the maximum possible reservable time slots. TRAFEEVOSCAN :  Number of scans for the counters in this object type. This counter is only valid for counters in object type TRAFEEVO. TSDCDL:  Number of time slots with one or more uplink or downlink TBFs currently reserved on dual carriers.

A Tower Mounted Amplifier (TMA) has a low noise figure and some gain. If it is mounted as closely as possible to the receive antenna, it can improve uplink sensitivity at the antenna, thus increasing the cell radius. There will be an improvement if the radio link is truly noise limited. If the system is uplink interference limited, there will be no improvement using a TMA. A TMA can degrade performance if the gain is set too high. There will be intermodulation effects due to larger signals, such as terminals close to the base station. Best results are achieved when the TMA gain is used to compensate for the feeder loss.

Proper frequency planning is essential in the development of a quality cellular system. Due to the limited amount of available RF spectrum, the scarcity of channels available to each operator, and the fact that most available frequencies are non-contiguous for most operators, frequencies must be reused throughout the system to increase network capacity. The frequencies are assigned such that there is minimal cochannel and adjacent channel interference between sites. Frequency reuse is based on hexagonal cell groupings called clusters. The size of the cluster will determine how the cluster is repeated throughout the network, i.e. the reuse pattern. The frequency reuse patterns are designated as N/F. Where N is the number of cell sites in a cluster and F is the number of frequency groups within a cluster. Ericsson uses 7/21 and 4/12 reuse patterns. The cluster patterns  In a 7/21 plan, there are 7 cell sites (A, B, . . . , G) and 21 frequency groups (A1, A2, A3, . . . , G1, G2,...

The environmental effects on the received signal produce interference and impairments in the form of Bit Error Rate (BER) . BER is defined as the ratio of the number of incorrect bits received versus the total number of bits. BER is estimated by the RBS on the reverse-link and by the MS on the forward-link. IS-136 does not state explicitly how the BER should be estimated but does specify the recommended accuracy for BER estimations. BER measures the effects of radio environment-introduced impairments which are discussed in the Speech Quality and Link Budget documents in this RF module.                           Coding of Estimated   BER Class BER BER Interval (%) 0 BER% < 0.01 1 0.01 ≤ BER% < 0.1 2 0.1 ≤   BER% < 0.5 3 0.5 ≤   BER% ...