URA or UTRAN Registration Area is a colection of cells that are used for fast moving UE’s in Connected mode when they are not transferring any data. In this case the UE is in CELL_PCH state. Everytime a fast moving UE in CELL_PCH state changes the cell, a CELL [...] Continue Reading…
HLR vs VLR
Home Location Register (HLR) and Visitors Location Register (VLR) are databases that contain the mobile subscriber information as per the GSM architecture. In general there is one central HLR per mobile network operator and one VLR per each Mobile Services Switching Centre (MSC) but this can vary according to [...] Continue Reading…
WiMAX vs Wifi
WiMAX and Wi-Fi are both wireless technologies but Wi-Fi can only be operated in short ranges (Max 250 m) and WiMAX could be operated in long ranges (around 30 Km). WiMAX has fixed and mobile version which could be used for several applications with higher bandwidth (around 40 Mbps). [...] Continue Reading…
LTE vs WiMAX
LTE (3GPP Long Term Evolution) and WiMAX (Wireless Interoperability for Microwave Access) are high speed 4G wireless technologies. 3G growth ends at HSPA+ and mobile operators started deploying 4G networks to offer more bandwidth to mobile handsets. These 4G technologies give virtual LAN reality to mobile handsets [...] Continue Reading…
3G vs 4G Network Technology | LTE and WiMAX | 3G vs 4G Speed, Frequencies and Features Compared | Battery Life more in 3G
3G and 4G are wireless communication technology classifications by certain standards and benchmarks. In the evolution of the mobile telephony the standards made for 3G and 4G network [...] Continue Reading…
4G vs LTE
4G, known as 4th generation of mobile communications, and LTE (Long Term Evolution) are 3GPP specifications for mobile broadband networks. Different eras of mobile communication are categorized into generations such as 1G, 2G, 3G, and 4G, where each generation has a number of technologies such as LTE. [...] Continue Reading…
A TMA – Tower Mounted Amplifier reduces system noise, improves uplink sensitivity and leads to longer UE battery life.
Sensitivity is the minimum input power needed to get a suitable signal-to-noise ratio (SNR) at the output of the receiver. It is determined by receiver noise figure, thermo noise power and required [...] Continue Reading…
UMTS uses a 3.84 Mcps chip rate on a 5Mhz carrier (effectively only using 3.84Mhz with the remaining bandwidth acting as a guard to adjacent frequencies). Since the maximum modulation in UMTS is QPSK 1/2, that means 1 bit per symbol, making the maximum raw throughput for a 5Mhz [...] Continue Reading…
1. CSSR (CALL SETUP SUCCESS RATE)
Definition: Rate of calls going until TCH successful assignment.
2. SCR (SUCCESSFULL CALL RATE)
Definition: Rate of calls going until normal release that is not interrupted by SDCCH DROP, neither by assignment failures, and neither by CALL DROP.
3. CALL DROP RATE (CDR)
Definition: Rate of all [...] Continue Reading…
RSCP: The “Received Signal Code Power” (RSCP) is the collected RF energy after the correlation / descrambling process, usually given in dBm. Only this code power is of interest for the following receiver stages when judging on the quality of the reception.
Ec/Io: This is the ratio of the [...] Continue Reading…
In Soft Handover, the UE connection consists of at least two radio links established with cells belonging to different RBSs. In Softer handover, the UE connection consists of at least two radio links established with cells belonging to the same RBS.
It acts as macro diversity since UE is connected [...] Continue Reading…
Capacity Management is responsible for the control of the load in the cell.
It consists of 3 main functions:
1. Dedicated Monitored Resource Handling: tracks utilization of critical resources of the system.
2. Admission Control: accepts/refuses admission requests based on the current load on the dedicated monitored resources and the characteristics of [...] Continue Reading…
Simply speaking, when the number of strong cells exceeds the active set size, there is “pilot pollution” in the area. Typically the active set size is 3, so if there are more than 3 strong cells then there is pilot pollution.
Definition of “strong cell”: pilots within the handover window [...] Continue Reading…
Eb_No is related to QOS of a service which in terms related to bit error rate.
Technically it is the minimum signal to noise needed by infrastructure equipment after despreading it signal. This is a value used to compare different infrastructure vendors. Eb_No changes with the service type.
For AMR 12.2 [...] Continue Reading…
CPICH power typically takes about 8~10% of the total NodeB power. For a 20W (43dBm) NodeB, CPICH is around 2W (35.1 ~ 33dBm).
In urban areas where in-building coverage is taken care of by in-building installations, the CPICH may sometimes go as low as 5% because:
1) The coverage area is [...] Continue Reading…
The power allocated to control channels may depend on equipment vendor recommendation. Typically no more than 20% of the total NodeB power is allocated to control channels, including CPICH. However, if HSDPA is deployed on the same carrier then the total power allocated to control channel may go up [...] Continue Reading…
• Overall system access control
– System information broadcasting
• Radio channel ciphering
– Radio channel ciphering
– Radio channel deciphering
– Radio environment survey
– Handover decision
– Macro-diversity control
– Handover control, execution, completion
– SRNS relocation
– Inter-system handover
• Radio resource management and control
– Radio bearer connection setup and release
– Reservation and release of physical [...] Continue Reading…
Channel bandwidth – 5MHz (10Mhz, 20Mhz)
Chip rate – 3.84Mchip/s
Frame length – 10ms
Channelisation spreading – variable spreading
Data modulation – QPSK(downlink), BPSK (uplink)
Spreading modulation – Balanced QPSK (downlink); Dual-channel QPSK (uplink)
Coherent detection – User dedicated time multiplexed pilot; Common pilot in downlink
Channel multiplexing in uplink – Control and pilot channel time [...] Continue Reading…
• Maximum User Bit Rates
– Rural Outdoor: 144kb/s (goal 384kb/s), up to 500km/h
– Suburban Outdoor: 384kb/s (goal 512kb/s), up to 120km/h
– Indoor/Urban Outdoor: 2Mb/s, max speed 10km/h
– Negotiation of bearer service attributes
– Parallel bearer services (service mix, multimedia)
– Circuit and packet switched bearers
– Scheduling of bearers
– Link adaptation [...] Continue Reading…
Radio wave propagation on radio channels is characterized by much reflection, diffraction and fading of signal energy. These are due to space obstacles, such as buildings and hills, which result in multipath propagation.
There’re Two effects of multipath propagation :
1. The code chip energies arrive at the receiver at distinguishable moments. [...] Continue Reading…
The main functions of Twin TMA is to decrease the noise as well as enhances the BTS receiver sensitivity and bring advantages for BTS coverage as follows:
1. Balance Uplink and Downlink
2. Increase Uplink Rx Level and Extend BTS Reverse Coverage
3. Decrease System Noise
4. Reduce Drop Call and Improve Call [...] Continue Reading…
TXPOWER is the phone’s transmitter power. We know that power control is guaranteed call quality and address the CDMA community interference tolerance and one of the key means of mobile phone from the base station near, uplink quality good, the mobile phone transmitting power is smaller, because at [...] Continue Reading…