1. 21-05-0822-02-0000 IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-07-0xxx-00-0000 Title: Suggestion about link parameters report Date Submitted: Jan 10, 2007 Presented at IEEE 802.21 session #18 in London, UK Authors or Source(s): Junxiang Guo, Yan Peng Abstract: This contribution proposes suggestion about delay trigger of link parameters report event.

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3. 21-05-0822-02-0000 Problem Currently when a QoS parameter value has crossed specified threshold level the link layer will immediately send a Link_parameters_report.indication to the MIH layer. This will cause problems, as occasionally a QoS parameter value maybe crosses threhold for a very tiny period but restores to normal level immediately, then the link layer will send a Link_parameters_report.indication event and cause the higher layer to take an action. In this case QoS value crossing threshold is only an occasional accident but it causes an unnecessary higher layer action, sometimes leads to frequent handover, in fact link layer need not report this event at all.

4. 21-05-0822-02-0000 Problem The below example figure illustrates the current problem: a kind of QoS parameter value crossed ExecuteActionThreshold and then restored to below this threshold level in a tiny period of 10 ms, in fact this is an occasional accident which occurs now and again, indeed it should not cause link parameters report.

5. 21-05-0822-02-0000 Solution How to avoid the aforementioned problem? We can add a time to delay the trigger of the link parameters report event. The below example figure illustrates this point. When add this trigger time, as the crossing event lasts a time short than the trigger time, the link layer will not report an unnecessary link parameters report event.

6. 21-05-0822-02-0000 Suggestion 7.5.4.1.2 Semantics of service primitive The primitive parameters are as follows: Link_Configure_Thresholds.request ( LinkParameterList ) Name TypeValid RangeDescription LinkParameterListListN/AA list of following set of parameters: LinkParameterType, InitiateActionThreshold, RollbackActionThreshold, ExecuteActionThreshold TriggerTime LinkParameterTypeA pair of {LinkType:Param­Type}. Examples: {Generic:Link Speed}, {Generic:Link Bit Error Rate}, {Generic:Link Frame Loss Rate before retransmission}, {Generic:Link Signal Strength}, {Generic:Link SINR}, {GPRS:BLER}, {GPRS:RxLevNCell} N/AParameters for which thresholds may be set InitiateAction­ThresholdThreshold values are dependent on parameter for which they are being set. N/AThreshold value which may cause MIH Users to start “setup” type activ­ities in response to actual parameter values crossing this threshold. RollbackAction­ThresholdThreshold values are dependent on parameter for which they are being set. N/AThreshold value which may cause MIH Users to cancel or rollback the above setup type operation if the actual parameter values retreat to this threshold. ExecuteAction­ThresholdThreshold values are dependent on parameter for which they are being set. N/AThreshold value which may cause MIH Users to execute taking appro­priate action if the actual parameter values cross this threshold. TriggerTimeInteger (0-5000) msIf changes in link parameters have crossed specified threshold levels and last for a period of time(TriggerTime), then link layer will trigger the Link_parameters_report.indication event. TriggerTime is passed from MIH user to MIH by configuration command and then MIH pass it to link layer.

7. 21-05-0822-02-0000 Suggestion Add a description in 7.5.10 as below: 7.5.10 Link_Parameters_Report.indication 7.5.10.1 Function Link_Parameters_Report indicates changes in link parameters have crossed specified threshold levels and last a period of specified time. This may include link layer parameters such as Speed of the link, QoS, BER, etc. The threshold level for each such parameter may have to be configured through a separate command to link layer.

8. 21-05-0822-02-0000 Thank you!