Internal inter-cell handover

Internal inter-cell handover occurs between channels pertaining to different cells of the same BSS. It only applies to multicell BSSs.

The use of this handover mechanism is optional for the GSM PLMN operator. However, if used, conformance to this test is mandatory.

The MSC may also invoke an internal inter-cell handover procedure. However, in that case the procedure is as for external handover.

Concerning synchronized or non-synchronized networks, the same applies to internal inter-cell handover as for external handover.

8.1.3.9.1.1 Normal case Test Purpose

To verify the normal internal handover procedure.

Test Case Initial Setup

O&M-messages as defined by the operator or the manufacturer shall be input on the OMC-interface setting the timer T3105 to an appropriate value B, the timer T8 to an appropriate value D, the parameter Ny1 to an appropriate value C, restricting the BSS to choose only one dedicated channel and commanding that the handover procedure will be controlled by the BSS.

A call shall be set up on a TCH between the radio interface and the MSC-interface.

Description

1. Conditions triggering an inter-cell handover decision in the BSS shall be established. The conditions are up to the operator and the manufacturer. The response on any interface shall be recorded.

2. HANDOVER ACCESS messages shall be input on the radio interface (of the new cell) on the main signalling link. The response on any interface shall be recorded.

3. A LAPDm SABM frame shall be input on the radio interface (of the new cell) on the main signalling link within a time B x C. The response on any interface shall be recorded.

4. Following immediately after step 3, a HANDOVER COMPLETE message shall be input on the radio interface on the main signalling link (of the new cell). The response on any interface shall be recorded.

Message flow

The messages from the BSSTE will be:

2. HANDOVER ACCESS on the Air interface, coded as specified in GSM 04.08 [4], 9.1.14 Handover reference = PAR1

3. A SABM LAPDm frame on the Air interface, coded as specified in GSM 04.06 [3]

4. A HANDOVER COMPLETE message on the Air interface, coded as specified in GSM 04.08 [4], 9.1.16.

Conformance Requirement

In the case of step 1, a HANDOVER COMMAND message shall occur on the radio interface (of the old cell) on the main signalling link.

In the case of step 2, a PHYSICAL INFORMATION message shall occur on the radio interface (of the new cell) on the main signalling link and repeatedly C times with an interval of B.

In the case of step 3, a LAPDm UA frame shall occur on the radio interface (of the new cell) on the main signalling link.

In the case of step 4, a HANDOVER PERFORMED message with an appropriate cause value shall occur on the MSC-interface.

The messages from the BSS shall be:

1. HANDOVER COMMAND on the Air interface, coded as specified in GSM 04.08 [4], 9.1.15 Handover reference = PAR1

2. PHYSICAL INFORMATION on the Air interface, coded as specified in GSM 04.08 [4], 9.1.28 3. A UA LAPDm frame on the Air interface, coded as specified in GSM 04.06 [3].

4. HANDOVER PERFORMED on the A-interface, coded as specified in GSM 08.08 [10], 3.2.1.25

Requirement reference GSM 04.08 [4], 3.4.4 GSM 08.08 [10], 3.1.7

8.1.3.9.1.2 No LAPDm connection Test Purpose

To verify the internal handover procedure when the MS does not establish the LAPDm on the signalling link.

Test Case Initial Setup

O&M-messages as defined by the operator or the manufacturer shall be input on the OMC-interface setting the timer T3105 to an appropriate value B, the timer T8 to an appropriate value D, the parameter Ny1 to an appropriate value C, and restricting the BSS to choose only one dedicated channel and commanding the BSS to control the handover procedure.

A call shall be set up on a TCH between the radio interface and the MSC-interface.

Description

1. Conditions triggering an inter-cell handover decision in the BSS shall be established. The conditions are up to the operator and the manufacturer. The response on any interface shall be recorded.

2. HANDOVER ACCESS messages shall be input on the radio interface (of the new cell) on the main signalling link. The response on any interface shall be recorded.

Message flow

MS BSS MSC HAND CMD

< HAND ACC | ---> | HAND ACC | ---> | . | . | PHYS INFO | <--- - | PHYS INFO T3105 | <--- - |

. | T8 . |

Ny1 | PHYS INFO | <--- |

CLEAR REQUEST

--->

The messages from the BSSTE will be:

2. HANDOVER ACCESS on the Air interface, coded as specified in GSM 04.08 [4], 9.1.14 Handover reference = PAR1

Conformance Requirement

In the case of step 1, a HANDOVER COMMAND message shall occur on the radio interface (of the old cell) on the main signalling link.

In the case of step 2, a PHYSICAL INFORMATION message shall occur on the radio interface (of the new cell) on the main signalling link and repeatedly C times with an interval of B. After the expiry of T8 or Ny1 times T3105 (B x C) a CLEAR REQUEST message concerning the old channel or the new channel, respectively, shall occur on the MSC-interface with the cause value: "Radio interface message failure".

The messages from the BSS shall be:

1. HANDOVER COMMAND on the Air interface, coded as specified in GSM 04.08 [4], 9.1.15 Handover reference = PAR1

2. PHYSICAL INFORMATION on the Air interface, coded as specified in GSM 04.08 [4], 9.1.28 CLEAR REQUEST on the A-interface, coded as specified in GSM 08.08 [10], 3.2.1.20

Cause = "Radio interface message failure"

Requirement reference GSM 04.08 [4], 3.4.4

GSM 08.08 [10], 3.1.7 and 3.1.5.3.3