What is time alignment timer LTE?
TimeAlignmentTimer is used to control how long the UE is considered uplink time aligned. The value of the timer is either UE specific (timeAlignmentTimerDedicated) and managed through dedicated signalling between the UE and the eNodeB, or cell specific (timeAlignmentTimerCommon) which is indicated in SIB2.
How does timing advance TA works in LTE?
In LTE, when UE wish to establish RRC connection with eNB, it transmits a Random Access Preamble, eNB estimates the transmission timing of the terminal based on this. Now eNB transmits a Random Access Response which consists of timing advance command, based on that UE adjusts the terminal transmit timing.
How many subcarriers are used for a 10 MHz FDD LTE channel?
50 601
Bandwidths
| Bandwidth | Resource Blocks | Subcarriers (downlink) |
|---|---|---|
| 5 MHz | 25 | 301 |
| 10 MHz | 50 | 601 |
| 15 MHz | 75 | 901 |
| 20 MHz | 100 | 1201 |
What is frame length in LTE?
In LTE, DL and UL transmissions are organized into radio frames of 10 ms each. Each frame is divided into ten equally sized subframes. The duration of each subframe is 1 ms. Moreover, each subframe is further divided into two equally sized time slots, that is, each slot is 0.5 ms.
What is uplink synchronization in LTE?
Abstract. Initial uplink synchronization (IUS) is a random access process in LTE that enables the eNodeB to detect, and uplink synchronize new user equipment. In future networks with huge number of devices, the number of simultaneous IUS users will increase significantly.
What is normal timing advance?
Most stock street engines call for 6 to 8 degrees of initial advance, but this is not set in stone. Engines with longer duration camshafts and other modifications often demand more initial timing. It’s not unusual to input 14 to perhaps 18 degrees of initial timing for engines with big cams.
What is TA and purpose of TA in LTE?
LTE Timing Advance Timing advance in GSM :- For GSM A Timing Advance (TA) is used to compensate for the propagation delay as the signal travels between the Mobile Station (MS) and Base Transceiver Station (BTS). The Base Station System (BSS) assigns the TA to the MS based on how far away it perceives the MS to be.
How is LTE downlink throughput calculated?
So the total bits carried by 300 subcarriers for the duration of a symbol is 300 X 6 = 1800 bits. Again 1 symbol is of 71.4 microseconds for LTE. So the data rate is 1800 / 71.4 = 25.2 Mbps. For 10 MHz using the same formula the maximum data rate in downlink is 50.4 Mbps and for 20 MHz it is 100.8 Mbps.
Why uplink speed is less than downlink in LTE?
Since a mobile station (cellphone) cannot afford to transmit at high power to compensate for this loss, it must transmit on a lower frequency as a lower frequency presents lesser free space path loss. Therefore, mobile-to-base station (uplink) frequencies are lower than base station-to-mobile(downlink) frequencies.
What is the duration of 1 sub frame in LTE?
Why SSS is placed before PSS?
SSS helps to achieve radio frame synchronization and deduce a pointer towards 1 of 168 Physical layer Cell Identity (PCI) groups. Below diagram shows how PSS and SSS helps finding the Physical Layer Cell ID.
What is preamble sequence in LTE?
The PRACH preamble consists of a cyclic prefix, useful part of the sequence and then a guard period which is simply an unused portion of time up to the end of the last subframe occupied by the PRACH. This guard period allows for timing uncertainty due to the UE to eNodeB distance.
How many eNodeB are in a TAC?
Tracking Area Codes (TACs) or TAs: it is group of eNodeBs in one small area with maximum number of 100 eNodeBs.
How do you calculate TA in LTE?
Timing Advance in LTE So a change of 1 in TA supposedly corresponds to a 156.14 meters in round-trip distance, or 78.07 meter one way (d = c * Ta / 2, where c = 299,792.458 m/sec, Ta = 16 * Ts, and Ts = 1/(15000*2048)).