ÍNDICE DE TABLAS
CAPÍTULO 2. INTRODUCCIÓN
2.2 PSICOLOGÍA DEL ESTRÉS
2.2.6 Otros constructos psicológicos relacionados con la evaluación del estrés
A successful call establishment contains
- Successful establishment of an RRC connection RRC connection Establishment provides the ability to establish an RRC connection, which is a logical connection, between the UE and UTRAN at L3. A radio connection comprises the connection between a UE and UTRAN including all the resources, i.e., L1, L2 and L3. The UE makes the initial access to UTRAN and requests for a RRC connection. Radio resources are allocated and a RRC connection is
established between UE and UTRAN.
- Successful establishment of a signaling connection
Signaling connection establishment provides the ability to establish a signaling connection between the UE and a core network, i.e. one signaling connection towards the CS core network and one towards the PS core network. Establishment of the first signaling connection is initiated by the UE as soon as the RRC connection is successfully established. An Iu control plane connection is then established between UTRAN and the core network. When a signaling
connection is already established towards one core network, the UE can initiate establishment of a second signaling connection to the other core network at any time. An Iu control plane
connection is then established between UTRAN and that other core network.
- Successful establishment of a RAB
RAB establishment provides the ability to establish of a user plane data stream within UTRAN.
In this chapter, the issues in RRC connection establishment will be investigated.
8.51.1 Symptoms
From the drive test, following symptoms will be observed by using TEMS and UETR:
- Case 1: The UE does not send out “RRC connection request” message to the UTRAN.
- Case 2: The UE receives “RRC connection setup” message and starts the transmission.
However, target RBS does not send out “Radio link restore indicator” to the RNC.
- Case 3: The UE receives “RRC connection setup” message and starts the transmission.
However, the UE does not send out “RRC connection setup complete” message to the UTRAN.
- Case 4: The UE receives “RRC connection setup” message and starts the transmission. After a while, the UE sends out “RRC connection setup complete” message to the UTRAN; however, the RRC connection establishment fails.
- Case 5: The UE receives “RRC connection reject” message with cause value “congestion”.
- Case 6: The UE receives “RRC connection reject” message with cause value “unspecified”.
- Case 7: The UE repeatedly sends “RRC connection request” messages but the number of transmission is less than N300 + 1 times.
- Case 8: The UE does not receive any message from the UTRAN.
8.51.2 Reason 1 – failure in RRC connection release
The reason for case 1 in chapter 8.51.1 probably is because of failure in the RRC connection release. If a RRC connection had been established, it is impossible to connect more than one RRC connection unless the previous RRC connection is released.
8.51.3 Reason 2 – uplink dedicated radio link synchronization failure
For case 2 in chapter 8.51.1, the UE receives “RRC connection setup” message and starts the transmission. However, target RBS does not send out “Radio link restore indicator” to the RNC.It implies the UE and UTRAN are trying to synchronize each other but uplink is not synchronized.
Solution
Please read chapter 8.53.
8.51.4 Reason 3 – downlink dedicated radio link synchronization failure
For case 3 in chapter 8.51.1, the UE receives “RRC connection setup” message and starts the transmission. However, the UE does not send out “RRC connection setup complete” message tothe UTRAN. It implies the UE and UTRAN are trying to synchronize each other but downlink is not synchronized.
Solution
Please read chapter 8.54.
8.51.5 Reason 4 – poor quality in uplink
For case 4 in chapter 8.51.1, the UE sends out “RRC connection setup complete” message to the UTRAN via the established dedicated channel; however, the RRC connection establishment still fails. It implies the UTRAN does not receive the “RRC connection setup complete” message.
Therefore, the possible reason is because of poor quality in uplink.
Solution
Please read chapter 8.60.
8.51.6 Reason 5 – connection rejected by load supervision function
At each request for establishment of a new RRC connection, it is checked that this is accepted by the processor load supervision function in the RNC. In case of reject from the load supervision function, the S-RCH will send “RRC connection reject” message to the UE and the procedure ends. The cause value of the message is “congestion”.
Solution
The engineer should re-dimension the capacity of the existing RNC. If need be, more processors are added.
8.51.7 Reason 6 – dedicated radio link setup failure
The reason for case 6 in chapter 8.51.1 is because of failure in the dedicated radio link setup.
Solution
Please read chapter 8.52.
8.51.8 Reason 7 – no suitable cell
Normally, the UE will repeatedly transmit “RRC connection request” in or more than N300 + 1 times if the UE does not receive any “RRC connection setup” message. Therefore, if the number of transmissions is less than N300 + 1 times, it implies “no suitable cell” event happens during RRC connection establishment.
Solution
Please read chapter 8.33.
Note:
1. 3GPP 25.331-V.3.7.0, which the P2.1 UTRAN follows, specifies that the number of the retransmissions of the “RRC connection request” should be N300 if the UE does not receive the
“RRC connection setup” message.
2. The number of retransmissions can be greater than N300 if the UE has received “RRC connection reject” message or re-select another cell. In this case, the UE counter V300 has been reset.
8.51.9 Reason 8 – S-CCPCH (FACH) failure
The “RRC connection reject” or “RRC connection setup” message is transmitted via S-CCPCH (FACH). If the UE does not receive any message from the UTRAN, the possible reason is because of S-CCPCH (FACH) failure.
In the P2 UTRAN, power of the S-CCPCH is not automatically modified with the variation of the network load. For that reason, the engineer has to carefully plan enough S-CCPCH power to fulfill the assumed downlink load. If mistake is done during the power calculation or the real load of the downlink carrier is larger than the assumed level, S-CCPCH might not cover the whole cell.
Solution
Please read chapter 8.8.
8.51.10 Reason 9 – random access procedure problem
Besides reasons 1 to 8, the last possible reason is because of the problem in the random access procedure. Due to this issue, the UTRAN does not receive the “RRC connection request”
message.
Solution
Please read chapter 8.36.