Communication control method and wireless relay apparatus
A communication control method using a wireless relay apparatus connected to an upper apparatus via a backhaul link includes, in a case that a backhaul link of the wireless relay apparatus fails to be recovered, by the wireless relay apparatus, executing a first process for re-establishing a backhaul link of a lower wireless relay apparatus connected to the wireless relay apparatus by using a first message of a BAP layer of the wireless relay apparatus; and executing a second process for re-establishing or releasing an access link of a user equipment connected to the wireless relay apparatus by using a second message of a layer different from the BAP layer.
1 . A communication control method executed in a wireless relay apparatus connected to an upper apparatus via a backhaul link, the communication control method comprising:
when the wireless relay apparatus joins a topology formed by at least one other wireless relay apparatus connected to a donor apparatus via at least one hop, receiving, from the donor apparatus, information for configuring a conditional handover to be executed in response to fulfillment of a condition, the information including a list of candidate cells;
receiving, from the upper apparatus, a failure notification transmitted in a case that a failure occurs in a backhaul link of the upper apparatus and that the upper apparatus fails to recover the backhaul link;
after receiving the failure notification, determining if the condition is met;
in a state in which the conditional handover is configured for the wireless relay apparatus, after receiving the failure notification from the upper apparatus and in response to determining that the condition is met, executing the conditional handover from the upper apparatus to a candidate cell included in the information received from the donor apparatus; and
performing re-establishment of the backhaul link with the upper apparatus if the condition is not met and the conditional handover is not executed.
2 . A wireless relay apparatus connected to an upper apparatus via a backhaul link, the wireless relay apparatus comprising:
a receiver configured to, when the wireless relay apparatus joins a topology formed by at least one other wireless relay apparatus connected to a donor apparatus via at least one hop, receive from the donor apparatus, information for configuring a conditional handover to be executed in response to fulfillment of a condition, the information including a list of candidate cells;
the receiver configured to receive, from the upper apparatus, a failure notification transmitted in a case that a failure occurs in a backhaul link of the upper apparatus and that the upper apparatus fails to recover the backhaul link;
a controller configured to determine if the condition is met after the receiver receiving the failure notification, the controller configured to, in a state in which the conditional handover is configured for the wireless relay apparatus, after receiving the failure notification from the upper apparatus and in response to determining that the condition is met, execute the conditional handover from the upper apparatus to a candidate cell included in the information received from the donor apparatus; and
wherein
re-establishment of the backhaul link with the upper apparatus is performed if the condition is not met and the conditional handover is not executed.
3 . An apparatus for controlling a wireless relay apparatus connected to an upper apparatus via a backhaul link, the apparatus comprising a processor and a memory, the processor configured to
when the wireless relay apparatus joins a topology formed by at least one other wireless relay apparatus connected to a donor apparatus via at least one hop, receive, from the donor apparatus, information for configuring a conditional handover to be executed in response to fulfillment of a condition, the information including a list of candidate cells,
receive, from the upper apparatus, a failure notification transmitted in a case that a failure occurs in a backhaul link of the upper apparatus and that the upper apparatus fails to recover the backhaul link,
after receiving the failure notification, determine if the condition is met, and
in a state in which the conditional handover is configured for the wireless relay apparatus, after receiving the failure notification from the upper apparatus and in response to determining that the condition is met, execute the conditional handover from the upper apparatus to a candidate cell included in the information received from the donor apparatus,
wherein re-establishment of the backhaul link with the upper apparatus is performed if the condition is not met and the conditional handover is not executed.
4 . A non-transitory computer-readable medium comprising, stored thereupon, computer program instructions for execution by a wireless relay apparatus connected to an upper apparatus via a backhaul link, the program instructions being configured to cause the wireless relay apparatus to execute processing of:
when the wireless relay apparatus joins a topology formed by at least one other wireless relay apparatus connected to a donor apparatus via at least one hop, receiving, from the donor apparatus, information for configuring a conditional handover to be executed in response to fulfillment of a condition, the information including a list of candidate cells;
receiving, from the upper apparatus, a failure notification transmitted in a case that a failure occurs in a backhaul link of the upper apparatus and that the upper apparatus fails to recover the backhaul link;
after receiving the failure notification, determining if the condition is met;
in a state in which the conditional handover is configured for the wireless relay apparatus, after receiving the failure notification from the upper apparatus and in response to determining that the condition is met, executing the conditional handover from the upper apparatus to a candidate cell included in the information received from the donor apparatus; and
performing re-establishment of the backhaul link with the upper apparatus if the condition is not met and the conditional handover is not executed.
5 . A system comprising:
a wireless relay apparatus connected to an upper apparatus via a backhaul link, wherein
the wireless relay apparatus is configured to:
when the wireless relay apparatus joins a topology formed by at least one other wireless relay apparatus connected to a donor apparatus via at least one hop, receive, from the donor apparatus, information for configuring a conditional handover to be executed in response to fulfillment of a condition, the information including a list of candidate cells;
receive, from the upper apparatus, a failure notification transmitted in a case that a failure occurs in a backhaul link of the upper apparatus and that the upper apparatus fails to recover the backhaul link;
after receiving the failure notification, determine if the condition is met; and
in a state in which the conditional handover is configured for the wireless relay apparatus, after receiving the failure notification from the upper apparatus and in response to determining that the condition is met, execute the conditional handover from the upper apparatus to a candidate cell included in the information received from the donor apparatus,
wherein re-establishment of the backhaul link with the upper apparatus is performed if the condition is not met and the conditional handover is not executed.