7.2.1.3Algorithm for Gcos Under Inaccurate Geo-Location Information

November 2016doc.:IEEE802.19-16/0181r10

IEEE P802.19.1a
Wireless Coexistence

Proposal

The text below is proposed for a coexistence discovery algorithm for GCOs under inaccurate geo-location information.

7.2.1.3Algorithm for GCOs under inaccurate geo-location information

Geo-location information not always provide accurate hidden neighbor information because of the followings: geo-location accuracy error. For example, based on FCC-15-47A1 all CBSDs must be able to determine their geographic coordinates (referenced to the North American Datum of 1983 (NAD83)) to an accuracy of ±50 meters horizontal and ±3 meters of elevation. Considering WLAN like systems with typical service coverage of 100m, ±50 meters horizontal accuracy can cause significant coexistence discovery failure resulted in hidden neighbors.

Only in some conditions (e.g., outdoors with clear line of site to GPS), accurate geo-location information is achievable

Other conditions, particularly indoors, it may be more challenging

To increase the accuracy of hidden neighbor discovery, a CM shall make good use of results of spectrum sensing (or radio measurement) by each GCO. That is, a CM shall get requried messurement results from GCO, for example, its registered AP, using requesting and obtaining measurements procedures in 5.2.7.

It isWe assumed that one CM and on CE are embeded in each AP which is a master GCO. A coexisetence discovery algorithm shall include the following steps as depcited Figure 1;

Eachmaster GCOAP and slave GCOSTA perform channel scanning

Each slave GCOSTA associates its selected master GCOAP

Each slave GCOSTA sends channel scanning information to the associated master GCOAP

Each CMAP discover hidden master GCOAPs and updates neighbor master GCOAP lists by comparing the followings; Channel scanning by master GCO itself, and channel scanning information to the associated slave GCOSTAs

If hidden masterGCOAPs are exist, the AP selects one or more STA among its associated STAs

The CMAP sends MasterGCOAPDiscovery_indication message to the selected slave GCOSTA(s). APDiscovery_indication message includes channel scanning information of the selected slace GCOSTA(s) and neighbor information regarding the associated master GCOAP of the selected slave GCOSTA(s)

The selected slave GCOSTA(s) received APDiscovery_indication message from its associated master GCOAP, send MasterGCOAPDiscovery_indication message to neighbor master GCOAPs discovered by the selected slave GCOSTA(s) based on channel scanning

Neighbor CMAP(s) received MasterGCOAPDiscovery_indication message, recognize existence of hidden master GCOAP(s) and update neighbor master GCOAP lists

Figure 1 Flow chart of hidden AP disocovery

Figure 2 depicts AP operation for hidden AP discovery.

Figure 2 Flow chart of AP operation

Figure 3 depicts STA operation for hidden AP discovery

Figure 3 Flow chart of STA operation

Figure 24 depicts an example of hidden master AP(GCO) situation. In this case, master AP1 (GCO1) has hidden neighbors, master AP2 (GCO2) and master AP3 (GCO3). Master GCOAP2 has a hidden neighbor, master GCOAP1. Master GCOAP3 has a hidden neighbor, master GCOAP1.

Figure 24An example of hiddenmaster AP(GCO)situation

As depicted in Fgure 35, after channel scanning and association, each master GCOAP and slave GCOSTA discovers the followings:

Master GCIAP1: no master GCOAP

Master GCOAP2: master GCOAP3

Master GCOAP3: master GCOAP2

Slave GCOSTA11: master GCOAP1

Slave GCOSTA21: master GCOAP2

Slave GCOSTA31: master GCOAP1, master GCOAP2, master GCOAP3

Slave GCOSTA32: master GCOAP2, master GCOAP3

Slave GCOSTA33: master GCOAP3

Slave GCOSTA1 may be associated with master GCOAP1. Slave GCOSTA2 may be associated with master GCOAP2. Slave GCISTA3, slave GCOSTA4, and slave GCOSTA5 1033 may be associated with master GCOAP3. Slave GCOSTA3 may be positioned in a region in which BSS1, BSS2, and BSS3 are overlapped with one another. Master GCOAP2, master GCOAP3, slave GCOSTA4 may be positioned in a region in which BSS2 and BSS3 are overlapped with each other.

Figure 35 An example of hidden master AP(GCO)situation after channel scanning and association

Figure 46 depicts how hidden neighbor master GCO information spread among the neighbors based on the suggested proposed algorithm.Master GCOAP3 shall transmit an master GCOAP discovery indication message including at least one of the information detected by the channel scanning procedure having been performed in master GCOAP3 and the master GCOAP list generated by master GCOAP3. Master GCOAP3 shall transmit the master GCOAP discovery indication message in a broadcast method, a multicast method, or a unicast method.

When transmitting the master GCOAP discovery indication message in the unicast method, master GCOAP3 shall transmit the master GCOAP discovery indication message to the slave GCOSTAthat detects the largest number of master GCOAPs through the channel scanning procedure among the slave GCOSTA3, slave GCOSTA4, and slave GCOSTA5 connected to master GCOAP3.

Slave GCOSTA3 has detected three APmaster GCOs,APmaster GCO1, APmaster GCO2, and APmaster GCO3 through the channel scanning procedure, STAslave GCO4 has detected two APmaster GCOs,APmaster GCO2 and APmaster GCO3 through the channel scanning procedure, and STAslave GCO5 has detected one APmaster GCO,APmaster GCO3 through the channel scanning procedure. Thus, APmaster GCO3 shall transmit the APmaster GCO discovery indication message to STAslave GCO3.

STASlave GCO3 shall receive the APmaster GCO discovery indication message from APmaster GCO3, and transmit the received APmaster GCO discovery indication message. In this case, STAslave GCO3 shall transmit the APmaster GCO discovery indication message in the broadcast method, the multicast method, or the unicast method.

Meanwhile, APmaster GCO1 and APmaster GCO2 shall receive the APmaster GCO discovery indication message transmitted from STAslave GCO3. That is, STAslave GCO3 means arbitrary terminal which is not associated to APmaster GCO1 or APmaster GCO2. When successfully receiving the APmaster GCO discovery indication message, APmaster GCO2 shall transmit, to STAslave GCO3, anAPmaster GCO discovery confirmation message that is a response to the APmaster GCO discovery indication message. The APmaster GCO discovery confirmation message transmitted by APmaster GCO2 shall include at least one of information for connection setup with APmaster GCO2 and operating channel information of APmaster GCO2. Alternatively, when successfully receiving the APmaster GCO discovery indication message, APmaster GCO2 shall transmit, to STAslave GCO3, a beacon message (which is used instead of the APmaster GCO discovery confirmation message) that is a response to the APmaster GCO discovery indication message. The beacon message may include at least one of information for connection setup with APmaster GCO2 and operating channel information of APmaster GCO2.

When successfully receiving the APmaster GCO discovery indication message, APmaster GCO1 may transmit the APmaster GCO discovery confirmation message that is the response to the APmaster GCO discovery indication message. The APmaster GCO discovery confirmation message transmitted APmaster GCO1 shall include information for connection setup with APmaster GCO1 and the operating channel information of APmaster GCO1. Alternatively, when successfully receiving the APmaster GCO discovery indication message, APmaster GCO1 shall transmit, to STAslave GCO3, a beacon message (which is used instead of the APmaster GCO discovery confirmation message) that is a response to the APmaster GCO discovery indication message. The beacon message may include at least one of information for connection setup with APmaster GCO1 and operating channel information of APmaster GCO1.

STASlave GCO3 shall transmit, APmaster GCO3, the APmaster GCO discovery confirmation message received from APmaster GCO1 and APmaster GCO2. When receiving the beacon message in response to the APmaster GCO discovery indication message from APmaster GCO1 and APmaster GCO2, STAslave GCO3 shall transmit the APmaster GCO discovery confirmation message which indicates that the APmaster GCO discovery indication message has been successfully received at each of APmaster GCOs (APmaster GCO1, APmaster GCO2) to APmaster GCO3.

APMaster GCO1 shall update the APmaster GCO list based on information included in the APmaster GCO discovery indication message. Specifically, APmaster GCO1 shall acquire, from the APmaster GCO discovery indication message, the information detected by the channel scanning procedure having been performed in APmaster GCO3. APMaster GCO1 may update the APmaster GCO list so as to include at least one APmaster GCO indicated by the information detected by the channel scanning procedure having been performed in APmaster GCO3. In particular, APmaster GCO1 shall determine, to be a hidden APmaster GCO, anAPmaster GCO which does not exist in the information detected by the channel scanning procedure having been performed in APmaster GCO1, but exists in the information detected by the channel scanning procedure having been performed in APmaster GCO3.

Alternatively, APmaster GCO1 shall acquire the APmaster GCO list generated by APmaster GCO3 from the APmaster GCO discovery indication message. APMaster GCO1 shall update the APmaster GCO list so as to include at least one APmaster GCO which exists in the APmaster GCO list generated by APmaster GCO3. In particular, APmaster GCO1 shall determine, to be a hidden APmaster GCO, an APmaster GCO which does not exist in the information detected by the channel scanning procedure having been performed in APmaster GCO1, but exists in the APmaster GCO list among the APmaster GCO lists generated by APmaster GCO3. For example, APmaster GCO1 shall determine, to be hidden APmaster GCOs, APmaster GCO2 and APmaster GCO3 based on the APmaster GCO discovery indication message.

APMaster GCO2 shall update the APmaster GCO list based on the information included in the APmaster GCO discovery indication message. The procedure of updating the APmaster GCO list in APmaster GCO2 shall be the same as the procedure of updating the APmaster GCO list in APmaster GCO1 described above.

Figure 46Spreading hidden neighbor master GCO information to the neighbors

Figure 7 depicts message exchange among APs and STAs.

Figure 7 Message exchange among APs and STAs

Submissionpage 1Hyunduk Kang, et al, ETRI