T3103 and T3105 differences?

Timer rr_t3103 (0-1000000, default 5000) used to determine switching dropped calls. Upon receipt of the target cell's switching success message or the source cell switching unsuccessful information, rr_t3103 will stop the clock. Upon receipt of the target cell's switching success message or the source cell switching unsuccessful information, rr_t3103 will stop the clock. Otherwise, once rr_t3103 to time, notify the MSC, remove the connection, dropped calls switch occurred. Otherwise, once rr_t3103 to time, notify the MSC, remove the connection, dropped calls switch occurred.Timer rr_t3105, used when asynchronous cell switch, determine whether the time right before Timer physical information (Physical information) in the GSM system, switching process, the mobile station receive network switch command, sent to the target channel switch access (HANDOVER ACCESS) message. Timer rr_t3105, when used in asynchronous cell switch, determine whether the time right before Timer physical information (Physical information) in the GSM system, switching process, the mobile station receive network switch command, sent to the target channel switch access (HANDOVER ACCESS) message. Network receive the message, calculate the RF characteristics, means the unit of data sent to the mobile station physical information, and start the timer T3105 (GSM 4.08 specification is defined as the T3105, Ericsson system parameters defined as TIMER3105). Network receive the message, calculate the RF characteristics, means the unit of data sent to the mobile station physical information, and start the timer T3105 (GSM 4.08 specification is defined as the T3105, Ericsson system parameters defined as TIMER3105). If the T3105 has not yet received the mobile station sent out the correct layer 2, the network will be re-issued physical information, and restart the T3105. If the T3105 has not yet received the mobile station sent out the correct layer 2, the network will be re-issued physical information, and restart the T3105. Physical information up to the number of retransmissions by the parameter "maximum number of physical information repeated up to the number of retransmissions by the parameter" maximum number of times to repeat

When the network switch to send the mobile station received access message, physical channel to be essential to achieve synchronization status. When the network switch to send the mobile station received access message, physical channel to be essential to achieve synchronization status. As long as the communication channel quality can be guaranteed to receive the mobile station should be able to correct physical information, and to send a layer 2 network structure of the frame. As long as the communication channel quality can be guaranteed to receive the mobile station should be able to correct physical information, and to send a layer 2 network structure of the frame. If the physical information sent to the mobile station can not receive after the issue of layer 2, typically, poor quality physical channel can not carry out normal communication, the appropriate increase in the number of physical information re-issued, so that the quality of the physical channel network in the upturn issued by the mobile station receives the layer 2 frames to complete the switching process, thus avoiding unnecessary dropped calls. If the physical information sent to the mobile station can not receive after the issue of layer 2, typically, poor quality physical channel can not normal communication, the appropriate increase in the number of physical information re-issued to the network at the physical change for the better channel quality to the mobile station when the received level 2 issued to complete the switching process, thus avoiding unnecessary dropped calls.
Handover access failure due to dropped calls of the main reasons: Handover access failure due to dropped calls of the main reasons:
? lack of signal strength coverage unstable, MS can not be properly received. ? lack of signal strength coverage unstable, MS can not be properly received. This mostly occurs in the course of an emergency switch. This mostly occurs in the course of an emergency switch. Cause MS can not normally receive PHYS INFO message. Cause MS can not normally receive PHYS INFO message.
Wrong switch, as the services may exist around the two communities with the BCCH of the cell, resulting in the activation of another system error plot of the TCH, MS PHYS INFO message can not be correctly received. Wrong switch, as the services may exist around the two communities with the BCCH of the cell, resulting in the activation of another system error plot of the TCH, MS PHYS INFO message can not be correctly received.
At present most of the Ericsson system, network, T3105 and NY1 are using the system default settings, specific to TIMER3105 = 4 (40 ms), NOOFPHYSINFOMSG = 35 (35 times). At present most of the Ericsson system, network, T3105 and NY1 are using the system default settings, specific to TIMER3105 = 4 (40 ms), NOOFPHYSINFOMSG = 35 (35 times). For some of the more serious interference with the network (such as China Unicom Network GSM900 1 × 1), 40 ms latency and 35 times the weight obviously not the right hair, the light of experience appropriate to improve T3105 and NY1 (NOOFPHYSINFOMSG), can effectively reduce the switching in dropped calls occurred. For some of the more serious interference with the network (such as China Unicom Network GSM900 1 × 1), 40 ms latency and 35 times the weight obviously not the right hair, the light of experience appropriate to improve T3105 and NY1 (NOOFPHYSINFOMSG), can effectively reduce the switching in dropped calls occurred.

The direct cause of dropped calls, there are two: 1, RF loss. The direct cause of dropped calls, there are two: 1, RF loss. 2, switch dropped calls (Note: The switch failure does not mean dropped calls, switching failure> switch dropped calls). 2, switch dropped calls (Note: The switch failure does not mean dropped calls, switching failure> switch dropped calls). The following analysis of these two cases. The following analysis of these two cases.
(1) RF loss (1) RF loss
A. A. Failure specification defines the downlink, mobile Taichung timer S (T100), in the beginning of the call the mobile station is assigned an initial value, that is, the wireless link timeout (radio_link_timeout). Failure specification defines the downlink, mobile Taichung timer S (T100), in the beginning of the call the mobile station is assigned an initial value, that is, the wireless link timeout (radio_link_timeout). This value is broadcast in the BCCH. This value is broadcast in the BCCH. Whenever the mobile station can not correctly decode a SACCH message (4 SACCH BLOCK) time, S minus 1. Whenever the mobile station can not correctly decode a SACCH message (4 SACCH BLOCK) time, S minus 1. Whenever the mobile station correctly decode a SACCH message, S plus 2. Whenever the mobile station correctly decode a SACCH message, S plus 2. However, the definition of S does not exceed radio_link_timeout initial. However, the definition of S does not exceed radio_link_timeout initial. When the S count is zero, the mobile station to give up radio resource connection, enter the idle mode. When the S count is zero, the mobile station to give up radio resource connection, enter the idle mode. Occur once dropped calls. Occur once dropped calls.
B. B. Uplink uplink failure failure
System failed to monitor the parameters of the uplink is link_fail. System failed to monitor the parameters of the uplink is link_fail. When the base station can not correctly decode a SACCH message, HDPC in the counter (the maximum value defined by the link_fail) minus 1, the base station correctly solved a SACCH message, the counter plus two (no more than Link_fail defined counter value). When the base station can not correctly decode a SACCH message, HDPC in the counter (the maximum value defined by the link_fail) minus 1, the base station correctly solved a SACCH message, the counter plus two (no more than Link_fail defined counter value). When the counter is zero, the base station to stop firing downlink SACCH, while start rr_t3109 timer (rr_t3109> T100). When the counter is zero, the base station to stop firing downlink SACCH, while start rr_t3109 timer (rr_t3109> T100). T100 timeout when the mobile station, mobile station back to idle mode, dropped calls occur. T100 timeout when the mobile station, mobile station back to idle mode, dropped calls occur. When the base station until the rr_t3109 timer to the release of wireless channel. When the base station until the rr_t3109 timer to the release of wireless channel. BSC also need to send a Clear request to the MSC message. BSC also need to send a Clear request to the MSC message.
Uplink and downlink failure of any party, will stop sending to each other SACCH. Uplink and downlink failure of any party, will stop sending to each other SACCH. Radio resource to start the process of releasing the other party. Radio resource to start the process of releasing the other party. TCH occurred in a link_fail, statistics for the first RF_LOSSES_TCH. TCH occurred in a link_fail, statistics for the first RF_LOSSES_TCH. Occurred in the SDCCH a link_fail, statistics for the first RF_LOSS_SD. Occurred in the SDCCH a link_fail, statistics for the first RF_LOSS_SD. In theory, the timer can shorten rr_t3109 early release of radio resources (to ensure rr_t3109> T100), to prepare for distribution to other mobile stations, can slightly reduce channel congestion. In theory, the timer can shorten rr_t3109 early release of radio resources (to ensure rr_t3109> T100), to prepare for distribution to other mobile stations, can slightly reduce channel congestion. Optimization process is actually not modified at all. Optimization process is actually not modified at all.
Parameters of wireless links Ultra (radio_link_timeout) will affect when the size of the drop call rate and the wireless network resource utilization. Parameters of wireless links Ultra (radio_link_timeout) will affect when the size of the drop call rate and the wireless network resource utilization. If set too small, it is easy to start handoff before, T100 time-out, resulting in dropped calls caused by wireless link failure. If set too small, it is easy to start handoff before, T100 time-out, resulting in dropped calls caused by wireless link failure. If you set too large, then the call quality is poor, the system a long time to release the radio resources to reduce resource utilization. If you set too large, then the call quality is poor, the system a long time to release the radio resources to reduce resource utilization.