November 2016 IEEE P802.15-16-0764-00-0008
IEEE P802.15
Wireless Personal Area Networks
Project / IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Title / Resolution for discovery text
Date Submitted / November 6th, 2016
Source / Marco Hernandez, Huan-Bang Li, F. Kojima (NICT)
Response / In response to Call for Contributions to TG8
Abstract
Purpose / For discussion in TG8
Notice / This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release / The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.
Submission Page XXX Hernandez, Li, Kojima (NICT)
November 2016 IEEE P802.15-16-0764-00-0008
Contents
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Submission Page XXX Hernandez, Li, Kojima (NICT)
November 2016 IEEE P802.15-16-0764-00-0008
1.1.1 Discovery proceduretypes
The discovery type is defined by the nexta higher layer. The MAC sublayer supports the following discovery types:
¾ One-way discovery: a PD either: transmits its discovery information during the discovery period and does not expect responses, or a PD detects discovery information during the discovery period. This is the advertisement type of discovery.
¾ Untargeted tTwo-way untargeted discovery: a requestor PD broadcasts the Discovery Request command frame contaning its discovery information during the CAP and it expects responses during the CAP from PDs that have detected such discovery information. discovered the broadcast message. This is the publish/subscribe type of discovery.
¾ Targeted tTwo-way targetted discovery: a requestor PD sends broadcasts the the Discovery Request command frame to a responder PD or PAC group, asking for its/their discovery information during the CAP. Responder PDs shall send the requested discovery information during the CAP. discovery information of PDs being queried and expects responses from PDs accordingly. This is the query/reply type of discovery.
1.1.2 Discovery information
The discovery information shall be defined as in Table 1 and set in the next higher layers.
1.1.2.1 One-way discovery
The procedure for one-way discovery follows the steps as shown in Figure 25.
One-way discovery allows fast transmission and detection of discovery information of peers in the surroundings by using a dedicated discovery period, where only 21 octets of discovery information are used per PD without encapsulating it in a MPDU. For details of the discovery signaling see X.
The discovery period is divided into discovery resources to transmit 21 octets per PD. After PDs achieved synchronization, PDs can either choose a discovery resource to transmit 21 octets or detect which PDs are transmitting their discovery information. Based on this information PDs can request to peer during the peering period. Choosing the discovery resource, which includes provisions for potential collisions, is performed in higher layers and out of the scope of the standard.
Transmission of discovery information during the discovery period:
a) The requestor PD's higher layer triggers the one-way discovery procedure by issuing the MLME-DISCOVERY.request primitive with the parameter DiscoveryType set to 0. The DiscoveryElement parameter is set in higher layers. A PD (i.e. PD1) broadcasts Discovery request message during discovery period.
b) Upton transmission of the discovery information, the MLME shall issue the MLME-DISCOVERY.confirm primitive with the status parameter of either SUCCESFUL or FAIL.A PD or PDs (i.e. PD2 ~ PD4) may scan during discovery period. After receiving the Discovery request message, the PD (i.e. PD2~ PD4) sends it to its the higher layer with an MLME-DISCOVERY.indication
Detection of discovery information during the discovery period:
a) The requestor PD's higher layer triggers the one-way discovery procedure by issuing the MLME-DISCOVERY.request primitive with the parameter DiscoveryType set to 1.
b) Upon reception of discovery information, the PD MAC sublayer shall issue the MLME-DISCOVERY.indication primitive to the next higher layer with the DiscoveryList parameter indicating a list of PDs discovery information.
Figure 25—One-way discovery procedure message sequence chart
1.1.3 Discovery procedure for two-way untargeted discovery
As shown in Figure 24, a general the discovery procedure for two-way targeted discovery mayshall contain the following steps:.
a) AThe requestor PD’s higher layer, such as PD1’s higher layer , triggers the two-way discovery procedure with anby issuing the MLME-DISCOVERY. Request with the parameter DiscoveryType set to 2.
b) Upon reception of the MLME-PEERING.request primitive, the requestor PD MAC sublayer broadcasts the Discovery Request command frame. The PD’s MAC, such as PD1’s MAC, broadcasts the Discovery request message.
c) Upon reception of a broadcast Discovery Request command frame, a PD shall issue the MLME-PEERING.indication primitive to its next higher layer, indicating two-way untargeted discovery request with the parameter X.A PD, such as PD2, scans during the discovery period and detects the Discovery request message.
d) The next higher layer of responder PDs shall issue a MLME-DISCOVERY.response primitive to their MAC sublayers, only in case such PDs decide to send the Peering Response command frame. The PD’s MAC, such as PD2’s MAC, sends the detected Discovery request message with an MLME-DISCOVERY.indication to its higher layer.
e) Upon reception of the MLME-DISCOVERY.response primitive, the MAC sublayer shall send the Discovery Response command frame to the requestor PD during the CAP. The Higher Layer receiving the Discovery request, such as PD2’s higher layer, decides either to send the Discovery response or not and indicates it to the MAC accordingly with an MLME-DISCOVERY.response.
f) Upon reception of the Peering Response command frame, the requestor PD shall send an Immediate Ack frame.The PD’s MAC, such as PD2’s MAC, sends Discovery response message to the discovery requester, such as PD1, if requested by the higher layer.
g) In case of Immidiate Ack frame is not received, responder PDs shall notify the next higher layer by issuing the x with parameter NO_ACK, The PD’s MAC, such as PD1’s MAC, sends the received Discovery response message to PD1’s higher layer with an MLME-DISCOVERY.confirm
h) A soon as the requestor PD sent the broadcast Discovery Request command frame, the Requestor PD shall monitor the CAP for possible Discovery Response command frames, until an application may cancel such monitoring.
i) Upon reception of Peering Response command frames, the requestor PD MAC sublayer shall issue the MLME-PEERING.confirm primitive with Status parameter of either SUCCESFUL or ACCESS_DENIED.
Figure 24—Two-way untargeted discovery procedure message chart
1.1.3.1 Untargeted two-way discovery
Untargeted two-way discovery follows the steps as shown in Figure 26.
Figure 26—Untargeted two-way discovery procedure message sequence chart
a) A PD (i.e. PD1) broadcasts Discovery request message during the CAP.
b) PDs (i.e. PD2 ~ PD4) may scan during discovery period. After receiving the Discovery request message, PDs (i.e. PD2 ~ PD4) send it to the higher layer.
c) Upon the higher layer MLME-DISCOVERY.response received, PDs (i.e. PD2 ~ PD4) respond to the sender PD (i.e. PD1) with a Discovery response message.
1.1.4 Targeted two-way discoveryDiscovery procedure for two-way targeted discovery
1.1.4.1
This process is after finding desired PDs. Targeted two-way discovery follows the steps as shown in Figure 27 The .procedure for two-way targeted discovery shall contain the following steps:
a) A PD (i.e. PD1) unicasts or multicasts Discovery Request message during the CAP.
b) PDs (i.e. PD2 ~ PD4) may scan during discovery period. After receiving the Discovery Request message, PDs (i.e. i.e. PD2 ~ PD4) send it to its higher layer with an MLME-DISCOVERY.indication.
Upon the Hhigher Llayer MLME-DISCOVERY.responseconfirm received, the queried PD (i.e. PD_queried) responds to the sender PD (i.e. PD1) with a Discovery Response message.
a) The requestor PD higher layer , triggers the two-way discovery procedure by issuing the MLME-DISCOVERY.Request with the parameter DiscoveryType set to 1, and DestinationAddress field with the responder PD MAC address or PAC group multicast address.
b) Upon reception of the MLME-PEERING.request primitive, the requestor PD MAC sublayer sends the Discovery Request command frame.
c) Upon reception of the Discovery Request command frame, the responder PD(s) shall issue the immediate Ack frame and the MLME-PEERING.indication primitive to its next higher layer, indicating two-way targeted discovery request with the parameter X.
d) The next higher layer of the responder PD(s) shall issue a MLME-DISCOVERY.response primitive to their MAC sublayers, indicating if such PDs accept or reject the request for discovery information within DiscoveryResponseTimeout.
e) Upon reception of the MLME-DISCOVERY.response primitive, the MAC sublayer shall send the Discovery Response command frame to the requestor PD during the CAP.
f) Upon reception of the Peering Response command frame, the requestor PD shall send an Immediate Ack frame. In case of Immidiate Ack frame is not received, responder PDs shall notify the next higher layer by issuing the x with parameter NO_ACK
g) Upon reception of Peering Response command frames, the requestor PD MAC sublayer shall issue the MLME-PEERING.confirm primitive with Status parameter of either SUCCESFUL or ACCESS_DENIED.
h) If the requestor PD does not receive Peering Response command frames within macDiscoveryResponseTimeout, the requestor PD shall discard the corresponding responder PD parameters and issue the MLME-PEERING.confirm primitive to the next higher layer with the Status parameter of CHANNEL_ACCESS_FAILURE
Figure 27—Two-way targeted discovery procedure message chart
1.1.4.2 Discovery procedure for many-to-many group
Many-to-many discovery is defined for a number of neighbouring PDs. Among these neighbouring PDs, any PD shall be able to communicate with all other PDs. Therefore, physical links must be available between any pair of PDs. Procedure for many-to-many discovery follows the steps as shown in Figure 28.
a) The I-PD’s MAC layer broadcasts Discover Request with its own PD ID (I-PD ID) and an empty list.
b) Each of the other PDs that captured the Discovery request sends an MLME-DISCOVERY.indication to its higher layer. A PD, that receives an MLME-DISCOVERY.response from its high layer, broadcasts Discovery response message. Hereafter, the responded PD is referred to as responder PD (R-PD). The Discovery response message is broadcasted with its own ID (R-PD ID), I-PD ID, and a list of IDs of all received PDs.
c) The I-PD broadcasts Discover request with its own PD ID (I-PD ID) and an updated list. The time period between the broadcasts of two Discovery request frames is referred to as random access duration Trar.
d) The random access period is repeated until the I-PD stops to further broadcast Discover request.
Figure 28—Discovery procedure sequence chart for forming many-to-many group
Submission Page XXX Hernandez, Li, Kojima (NICT)