DELIVERY OF PROTOCOL DATA UNITS
Delivery of protocol data units or other suitable data or information units in various communication systems can be enhanced by appropriate methods and devices. For example, in-sequence delivery of protocol data units received in parallel from several lower-layer acknowledged-mode protocol entities may benefit from timers and/or forwarding status reports. A method can include observing a gap in a sequence of protocol data units received from a plurality of lower-layer protocol entities providing data transfer. The method can also include starting a timer upon the gap observation. The method can further include preventing the gap from blocking delivery of service data units to a higher layer, when the timer expires. The method can additionally include detecting a forwarding-status report. The method can also include immediately proceeding with data delivery to higher layer, containing the gaps because of the lack of forwarding at handover.
1 . A method, comprising:
observing a gap in a sequence of protocol data units received from a plurality of lower-layer protocol entities providing data transfer;
starting a timer upon the gap observation; and
preventing the gap from blocking delivery of service data units to a higher layer, when the timer expires.
2 . The method of claim 1 , further comprising:
configuring the timer's expiry value by radio resource control.
3 . The method of claim 1 , wherein the preventing is carried out by proceeding with the delivery of service data units to the higher layer without a delay caused by waiting for protocol data units.
4 . The method of claim 1 , wherein reception of the protocol data units from more than one lower-layer protocol entities is at least substantially parallel in nature and the plurality of lower-layer protocol entities are acknowledged-mode protocol entities.
5 . The method of claim 1 , wherein the starting the timer is further contingent upon determining whether use of the timer is activated or deactivated.
6 . A method, comprising:
receiving a control data unit, the control data unit identifying at least one protocol data unit that should not be expected to be received; and
preventing the at least one identified protocol data unit from blocking delivery of service data units to a higher layer.
7 . The method of claim 6 , wherein the identifying the at least one protocol data unit is carried out by using sequence numbers.
8 . The method of claim 6 , wherein the preventing is carried out by proceeding with the delivery of service data units to a higher layer without a delay caused by waiting for protocol data units.
9 . The method of claim 6 , wherein the control data unit identifies at least one protocol data unit that should be expected to be received.
10 . A method, comprising:
determining at least one protocol data unit that will not be delivered to a data-receiving entity; and
sending a control data unit, identifying the at least one protocol data unit.
11 . The method of claim 10 , wherein the identifying the at least one protocol data unit is carried out by using sequence numbers.
12 . The method of claim 10 , wherein the control data unit identifies one or more protocol data units that should be expected to be received.
13 . The method of claim 10 , further comprising:
awaiting confirmation of reception of the control data unit; and
retransmitting the control data unit when confirmation is not received within a predetermined amount of time.
14 . The method of claim 10 , wherein the sending is contingent on a prior determination of whether or not to send the control data unit based on whether the delivery of protocol data units will not take place.
15 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to
observe a gap in a sequence of protocol data units received from a plurality of lower-layer protocol entities providing data transfer;
start a timer upon the gap observation; and
prevent the gap from blocking delivery of service data units to a higher layer, when the timer expires.
16 . The apparatus of claim 15 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to configure the timer's expiry value by radio resource control.
17 . The apparatus of claim 15 , wherein the preventing is carried out by proceeding with the delivery of service data units to the higher layer without a delay caused by waiting for protocol data units.
18 . The apparatus of claim 15 , wherein reception of the protocol data units from more than one lower-layer protocol entities is at least substantially parallel in nature and the plurality of lower-layer protocol entities are acknowledged-mode protocol entities.
19 . The apparatus of claim 15 , wherein the starting the timer is further contingent upon determining whether use of the timer is activated or deactivated.
20 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to
receive a control data unit, the control data unit identifying at least one protocol data unit that should not be expected to be received; and
prevent the at least one identified protocol data unit from blocking delivery of service data units to a higher layer.
21 . The apparatus of claim 20 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to identify the at least one protocol data unit by using sequence numbers.
22 . The method of claim 20 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to prevent the blocking of delivery by proceeding with the delivery of service data units to a higher layer without a delay caused by waiting for protocol data units.
23 . The apparatus of claim 20 , wherein the control data unit is configured to identify at least one protocol data unit that should be expected to be received.
24 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to
determine at least one protocol data unit that will not be delivered to a data-receiving entity; and
send a control data unit, identifying the at least one protocol data unit.
25 . The apparatus of claim 24 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to identify the at least one protocol data unit by using sequence numbers.
26 . The apparatus of claim 24 , wherein the control data unit is configured to identify one or more protocol data units that should be expected to be received.
27 . The apparatus of claim 24 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to
await confirmation of reception of the control data unit; and
retransmit the control data unit when confirmation is not received within a predetermined amount of time.
28 . The apparatus of claim 24 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to send the control data unit contingent on a prior determination of whether or not to send the control data unit based on whether delivery of protocol data units will not take place.