S1 interface – A Single Interface between LTE RAN and evolved packet core The S1 interface is the interface between the LTE RAN and evolved packet core. S1 interface protocol stack is described in Figure. S1 performs the following functions: S1-UP (user plane) S1-CP (control plane) LTE S1-UP (user plane) The S1 user plane external … Read more
Different modulation methods corresponding to different transmitting abilities in air interface. R99/R4: QPSK HSDPA: QPSK or 16QAM The UTRAN air interface uses QPSK modulation in the downlink, although HSDPA may also employ 16 Quadrature Amplitude Modulation (16QAM). 16QAM requires good radio conditions to work well. As seen, with 16QAM also the amplitude of the signal … Read more
The air interface is the radio-based communication link between the mobile station and the active base station. LTE air interface supports high data rates. LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) for downlink transmission to achieve high peak data rates in high spectrum bandwidth. LTE uses Single Carrier Frequency Division Multiple Access (SC-FDMA) for … Read more
The 3G Iub interface is the terrestrial interface between NodeB and RNC. The Radio Network Layer defines procedures related to the operation of the WCDMA NodeB. The Transport Network Layer defines procedures for establishing physical connections between the 3G NodeB and the 3G RNC. The 3G Iub application protocol, WCDMA NodeB application part (NBAP) initiates … Read more
Here I write about Iu PS Interface in WCDMA. WCDMA Protocol Structure for Iu PS The Iu PS protocol structure is represented in below image. Again, a common ATM transport is applied for both User and Control Plane. Also the physical layer is as specified for wcdma Iu CS. WCDMA Iu PS Control Plane Protocol … Read more
The concept of Interference Rejection Combining (IRC) is to regenerate the transmitted signal based on the estimated data from the previous receptions, emulate the distortion occurring from the multi-path channels and, finally subtract all regenerated interfering signals from the uplink received signals to obtain more reliable estimation of original users’ data. This feature utilizes the … Read more
Margin sites intrusive noise levels due to an increase can be considered as If sites were spaced closer together than position using the same frequency The thermal noise floor. In other words, the system is interference limited as Opposed to limit noise. Often a site link budget maximum range is used to evaluate the process. … Read more