Fast moving scenario access point switching

Embodiments of a system and method for switching access points in a fast moving scenario in a wireless network are generally described herein. In some embodiments, an apparatus of a communication station (STA) includes transceiver circuitry to: send a request to a first access point (AP) to associate with the first AP to access a network, and receive a service set identifier (SSID), a channel number, an ordered listing of APs for association when traveling in a fast moving scenario, and a plurality of basic service set identifications (BSSIDs) corresponding to the ordered listing of APs. The apparatus includes processing circuitry to determine whether a signal strength of a second AP exceeds a signal strength of the first AP in the fast moving scenario fast moving scenario access point switching.

CLAIM OF PRIORITY

This patent application is a U.S. National Stage Application under 35 U.S.C. 371 from International Application No. PCT/CN2015/097710, filed Dec. 17, 2015, published as WO 2017/101070, which is incorporated herein by reference.

TECHNICAL FIELD

Embodiments pertain to wireless communications. Some embodiments relate to associating a station to a wireless access point.

BACKGROUND

There are often may wireless access points (APs) that are accessible in a city. A user accesses the internet through one of these wireless hotspots. One issue with communicating data over a wireless network is that switching from one AP to another AP takes time and causes interruptions in service.

DETAILED DESCRIPTION

Wireless hotspots are prevalent in many cities. Users may access a network, such as the internet through these wireless hotspots. An example wireless hotspot is a WiFi hotspot, which may be used to access a Wireless Wide Area Network (WWAN) infrastructure. For example, a WiFi hotspot, access point (AP), or communication station (STA) may conform to a Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards. WiFi best supports connections with a communication Station (STA) in a static or slow moving scenario (i.e., when the STA is moving slowly). If the STA is roaming in a fast moving scenario (i.e., when the STA is moving quickly), accessing and switching access points (APs) may be difficult, and throughput may drop sharply. In some examples in a fast moving scenario, a STA may not be able to send or receive data successfully due to the long re-association latency during AP switching. In fast moving scenarios, WiFi roaming and frequent AP switching may cause poor user experience. The complicated and long time pendency of AP switching is inefficient.

In legacy systems, when a STA attempts to switch to a new AP in a fast moving scenario, the STA takes a long time to switch to a new AP and once associated, may have already moved out of range of the new AP. In another example, the STA may switch to the new AP in time and remain in range, but may already be leaving the range of the new AP and be in better range of another AP. The legacy roaming and re-association systems are not suitable for a fast moving scenario. A new roaming system may simplify re-association flow to adapt to fast movement and make the WWAN network seamless for the user experience of a STA.

In a fast moving scenario, such as a WiFi STA of a user riding on a bus in a city or on an express highway. In an example, there are two common features of a fast moving scenario: a vehicle moving quickly along a fixed route and an initial station, (e.g., a stop before a route, a bus station, a charging window of an express highway, a train stop, etc.). These two features may be combined with a new re-association technique to adapt the fast moving scenario for WiFi STA. WiFi APs may be deployed along a route (e.g., bus route or train route), a service set identifier (SSID) and a channel number may be assigned for the APs, and basic service set identifier (BSSIDs) for the deployed APs may be determined.

When a vehicle stops in a station or charging window for the first time, the stop time is enough for the WiFi STA to associate the network, and the AP at the station or charging window may transfer relevant information (e.g., the BSSID, position, channel number, etc.) of the next APs in order to the newly associated STA. When the vehicle runs to a middle position between a first AP and a second AP, the STA may take advantage of the known next AP information and associate with the next AP actively. In an example, the STA does not need to detect the second AP through Probe_Req or Probe_Resp packets. In another example, the authentication procedure may be optimized at the first AP to join a network, without using Auth_Req or Auth_Resp during AP switching. These examples result in time saved during AP switching in the fast moving scenario.

The legacy roaming and re-association system uses three steps for a handshake. In an example, the new design uses only the third one (i.e., Asso_Req and Asso_Resp). This may improve efficiency of re-association when a STA is in a fast moving scenario and improve AP switching. Of the three steps for a handshake for AP switching, the first step, probe, uses the most time. Approximately hundreds of milliseconds (e.g., where a STA probes an AP actively) or thousands of milliseconds (e.g., where a STA listens for a beacon in each channel passively) may be consumed. Both of these scenarios require a long time relatively in wireless communication, which causes unreliability and failures in the fast moving scenario. Statistical averages include consuming 300˜500 ms in the probe stage, or approximately rounded down to 300 millisecond, 1 ms for the authentication stage, and 1 ms for the association stage. The comparison ratio between the new and legacy techniques is: 1 ms/302 ms=0.33%. The new technique exhibits more efficiency than current solution by a large ratio.

FIG. 1is a functional diagram100illustrating access point (AP) switching in accordance with some embodiments.FIG. 1shows a legacy process for a STA102to switch between a first AP104and a second AP106. In the first view, the STA102must disconnect from the first AP104, before sending a probe request in the second view. The second view shows a probe response from the second AP106sent to the STA102, which then may associate with the second AP106, as shown in the third view. The new technique may eliminate the disconnection, probe request, and probe response shown in the first two views and may instead jump straight to the third view and associate with the second AP106.

FIG. 2is a functional diagram200illustrating an initial configuration for fast-moving AP switching in accordance with some embodiments. In an example, multiple APs may be deployed along a fixed route, such as a first AP204, a second AP206, etc. The basic info of these APs, such as a BSSID, a channel number, and a position may be known and saved, such as at a server. The STA202may receive information about the APs from the first AP204, such as at a bus station. The STA202may associate with a network when a bus carrying the STA202stops at a station. The initial information may be sent to the STA202from a server and saved in memory of the STA202in sequence. In an example, AP coverage area may slightly overlap between neighbor APs, as shown in diagram200with the range of the first AP204and the range of the second AP206overlapping at a middle position.

FIG. 3is a functional diagram300illustrating a switching configuration for fast-moving AP switching in accordance with some embodiments.FIG. 3shows the STA302in a middle position between a first AP304and a second AP306. The STA302may switch from the first AP304to the second AP306at the middle position.

When a vehicle runs along the fixed route toward the second AP306, the STA302may trigger an association with the second AP306actively after the STA302arrives at the middle position. The middle position may include a GPS determined middle position or the middle position may include a position where the STA302receives an equal received signal strength indicator (RSSI) between the first AP304and the second AP306, or where the RSSI from the second AP306exceeds the RSSI from the first AP304. From this position and moving forward along the fixed route, the signal from the second AP306will become stronger and the signal from the first AP304will become weaker. The STA302may switch APs at the middle position.

In another example, the STA302may receive a real time position through global positioning system (GPS) circuitry of the STA302and trigger the AP switching process when the STA302arrives at the middle position. The location of the middle position may be predetermined and stored at the STA302. The middle position may be predetermined along the route before the STA302starts along the route, and the predetermined middle position may be sent by the first AP304to the STA302.

In an example, the STA302does not wait to disconnect from the first AP304before associating with the second AP306. By not waiting, the switch may be more efficient and may remove latency. By removing the probe and authentication aspects of the handshake time to associate with a new AP is greatly reduced.

In an example, the STA302may not be able to connect to the second AP306and may not be able to receive RSSI information from the second AP306. The STA302may use a different channel than the first AP304to connect to the second AP306. In this example, the STA302may utilize GPS to switch to the second AP306when the STA302is in the middle position. The STA302may determine when to connect to a third AP using RSSI. The STA302may connect to the third AP using a second channel that was used to connect to the second AP306. The APs along the route of the STA302may have corresponding channels provided to the STA302at the first AP304.

FIG. 4is a functional diagram400illustrating multiple configurations for fast-moving AP switching in accordance with some embodiments.FIG. 4shows a STA402in multiple configurations at different positions along a route, such as a route of a public transportation vehicle. The STA402in the first position receives configuration information from a first AP404. The STA402switches at a first middle position to a second AP406. At a later middle position, the STA402may switch to an nth AP408.

In an example, the technique described herein includes a change to open systems interconnection (OSI) layer 2 switching (e.g., MAC layer or data link layer) of an AP or STA. An AP connects to a higher layer router using the MAC layer. In systems with multilayer switching (MLS), the MAC layer switching uses less time than layer 3 (e.g., IP layer or network layer) switching.

The benefits of switching APs in the fast moving scenario is amplified by switching at layer 2 over layer 3.

FIG. 5illustrates a bus route500with APs (e.g.,506-518) along the route in accordance with some embodiments.FIG. 5includes a bus502, a bus station504, and a first AP506. A user on the bus502may request WiFi access along the bus route on a STA. The first AP506may receive the request from the STA. In response, the first AP506may determine a path the bus502will take including an ordered listing of APs from AP508to AP518. The first AP506may assign a service set identifier (SSID) and a channel number of the APs508-518in the ordered listing. The first AP506may identify a plurality of basic service set identifications (BSSIDs) corresponding to the APs508-518in the ordered listing. The first AP506may transmit an association response to the STA indicating successful association and transmit the ordered listing of APs508-518, as well as the SSID, the channel number, and the plurality of BSSIDs corresponding to the APs508-518.

After the STA receives this information from the AP506, the STA on the bus502may use the SSID and the channel number and use the plurality of BSSIDs, each corresponding to one of APs508-518to connect to each of the APs506-518. In an example, the SSID and the channel number are the same for each AP in the ordered listing508-518. In another example, the AP506also shares the SSID and channel number. The STA is located on the bus502, and moves with the bus502in a fast moving scenario. As the bus502leaves the station504, the STA moves along the path determined by the first AP506. The STA reaches a point along the path between the first AP506and a second AP508where the signal strength of the second AP508exceeds the signal strength of the first AP506. When that point is reached, the STA may switch from using the first AP506to using the second AP508, without changing the SSID or channel number. In an example, the STA may switch without sending a probe request, receiving a probe response, sending an authentication request, or receiving an authentication response from the second AP508.

FIG. 6A-Billustrate representations of example test results in a fast moving scenario.FIG. 6Ashows a table of test results for various tests andFIG. 6Bshows a graphical representation of the data in the table ofFIG. 6A. The simulations illustrated inFIG. 6A-Bincluded test conditions of 8 mbps internet traffic, a SISO antenna, and dynamic modulation-and-coding scheme (MCS) selection. As seen inFIG. 6A-B, the new technique for switching APs in a fast moving scenario has throughput significantly higher than the legacy technique.

FIG. 7illustrates the operation of a technique700for switching APs in a fast moving environment in accordance with some embodiments. The technique700includes an operation702to send a request to a first access point, for example, using transceiver circuitry of an apparatus of a STA. The technique700includes an operation704to receive an ordered listing of access points for association when the STA is traveling in a fast moving scenario. Operation704may include receiving a SSID and a channel number with the ordered listing of access points. Operation704may include receiving a plurality of BSSIDs corresponding to the ordered listing of APs.

The technique700includes an operation706to determine whether a signal strength of a second access point exceeds a signal strength of the first access point in the fast moving scenario. For example, to determine whether the signal strength of the second AP exceeds the signal strength of the first AP may include to determine using processing circuitry of an apparatus of a STA. The STA may include memory, an antenna, and a display screen. The signal strength may be measured by received signal strength indicators (RSSIs). In another example Operation706may include determining whether the STA has reached a middle position, using GPS, between the first AP and the second AP.

The technique700includes an operation708to send an association request to the second access point to associate with the second access point when the signal strength of the second access point exceeds the signal strength of the first access point in the fast moving scenario. Operation708may include to send the association request by using the SSID, the channel number, and a BSSID of the plurality of BSSIDs, where the BSSID corresponds to the second AP, and the SSID and the channel number may be used for all of the APs.

In an example, the first AP is listed first and the second AP is listed second in the ordered listing of APs. In another example, the STA may associate with the second AP without first disconnecting from the first AP. The STA may associate with the second AP without sending a probe request or authentication request, receiving a probe response or authentication response, or without detecting the second AP. The first AP may be located at a bus terminal (or other public transportation terminal), and the ordered listing of APs may be physically arranged along a route of the bus (or other public transportation vehicle), starting at the bus terminal. The second AP, for example, may be just outside the bus terminal

Machine (e.g., computer system)800may include a hardware processor802(e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory804and a static memory806, some or all of which may communicate with each other via an interlink (e.g., bus)808. The machine800may further include a display unit810, an alphanumeric input device812(e.g., a keyboard), and a user interface (UI) navigation device814(e.g., a mouse). In an example, the display unit810, alphanumeric input device812and UI navigation device814may be a touch screen display. The machine800may additionally include a storage device (e.g., drive unit)816, a signal generation device818(e.g., a speaker), a network interface device820, and one or more sensors821, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine800may include an output controller828, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

The storage device816may include a machine readable medium822that is non-transitory on which is stored one or more sets of data structures or instructions824(e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions824may also reside, completely or at least partially, within the main memory804, within static memory806, or within the hardware processor802during execution thereof by the machine800. In an example, one or any combination of the hardware processor802, the main memory804, the static memory806, or the storage device816may constitute machine readable media.

VARIOUS NOTES & EXAMPLES

Each of these non-limiting examples may stand on its own, or may be combined in various permutations or combinations with one or more of the other examples.

Example 1 is an apparatus of a communication station (STA), the apparatus comprising processing circuitry and memory configured to: configure a request for transmission to a first access point (AP) to associate with the first AP to access a network; decode a service set identifier (SSID), a channel number, an ordered listing of APs for association when traveling in a fast moving scenario, and a plurality of basic service set identifications (BSSIDs) corresponding to the ordered listing of APs; determine whether a signal strength of a second AP exceeds a signal strength of the first AP in the fast moving scenario; and in response to determining that the signal strength of the second AP exceeds the signal strength of the first AP in the fast moving scenario, configure an association request for transmission to the second AP to associate with the second AP to access the network using the SSID, the channel number, and a BSSID of the plurality of BSSIDs, the BSSID corresponding to the second AP.

In Example 2, the subject matter of Example 1 optionally includes, wherein the SSID applies to the APs in the ordered listing of APs.

In Example 3, the subject matter of any one or more of Examples 1-2 optionally include, wherein the first AP is a wireless AP operating in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 network.

In Example 4, the subject matter of any one or more of Examples 1-3 optionally include, wherein the first AP is listed first and the second AP is listed second in the ordered listing of APs.

In Example 5, the subject matter of any one or more of Examples 1-4 optionally include, wherein to configure the association request for transmission to the second AP to associate, the processing circuitry is to configure the association request for transmission to the second AP to associate without first disconnecting from the first AP.

In Example 6, the subject matter of any one or more of Examples 1-5 optionally include, wherein to configure the association request for transmission to the second AP to associate, the processing circuitry is to configure the association request for transmission to the second AP to associate without first sending an authentication request.

In Example 7, the subject matter of Example 6 optionally includes, wherein to configure the association request for transmission to the second AP to associate, the processing circuitry is to configure the association request for transmission to the second AP to associate without first receiving an authentication response.

In Example 8, the subject matter of any one or more of Examples 1-7 optionally include, wherein to configure the association request for transmission to the second AP to associate, the processing circuitry is to configure the association request for transmission to the second AP to associate without detecting the second AP.

In Example 9, the subject matter of Example 8 optionally includes, wherein to configure the association request for transmission to the second AP to associate without detecting the second AP, the processing circuitry is to refrain from sending a probe request to the second AP.

In Example 10, the subject matter of Example 9 optionally includes, wherein to configure the association request for transmission to the second AP to associate without detecting the second AP, the processing circuitry is to refrain from decoding a probe response from the second AP.

In Example 11, the subject matter of any one or more of Examples 1-10 optionally include, wherein the ordered listing of APs correspond to a physical arrangement of the APs along a route of a bus starting at a bus terminal.

In Example 12, the subject matter of any one or more of Examples 1-11 optionally include, wherein the processing circuitry is to decode a first received signal strength indicator (RSSI) from the first AP and a second RSSI from the second AP; and wherein to determine that the signal strength of the second AP exceeds the signal strength of the first AP, the processing circuitry is to determine that the second RSSI exceeds the first RSSI.

In Example 13, the subject matter of any one or more of Examples 1-12 optionally include, further comprising a transceiver, the transceiver being configured by the processing circuitry for transmission and reception.

In Example 14, the subject matter of Example 13 optionally includes, further comprising one or more antennas coupled to the transceiver.

Example 15 is an apparatus of an access point (AP) comprising memory and processing circuitry to: determine a path including an ordered listing of APs for association when a communication station (STA) travels in a fast moving scenario; assign a service set identifier (SSID) and a channel number to APs in the ordered listing of APs; identify a plurality of basic service set identifications (BSSIDs) corresponding to the ordered listing of APs; receive a request from the STA to associate with the AP to access a network in the fast moving scenario; configure, for transmission, an association response to the STA indicating successful association; configure, for transmission, the ordered listing of APs, the SSID, the channel number, and the plurality of BSSIDs to the STA.

In Example 16, the subject matter of Example 15 optionally includes, wherein the SSID applies to all APs in the ordered listing of APs.

In Example 17, the subject matter of any one or more of Examples 15-16 optionally include, wherein the wireless AP is a wireless AP operating in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 network.

In Example 18, the subject matter of any one or more of Examples 15-17 optionally include, wherein the wireless AP is listed first in the ordered listing of APs.

In Example 19, the subject matter of any one or more of Examples 15-18 optionally include, wherein the wireless AP is located at a bus terminal and the ordered listing of APs correspond to a physical arrangement of the APs along a route of a bus starting at a bus terminal.

In Example 20, the subject matter of any one or more of Examples 15-19 optionally include, wherein the transceiver is to: transmit a first received signal strength indicator (RSSI) to the STA; and when a second RSSI received by the STA from a second AP exceeds the first RSSI, receive an indication from the STA disconnecting the STA from the wireless AP.

In Example 21, the subject matter of any one or more of Examples 15-20 optionally include further comprising a transceiver, the transceiver being configured by the processing circuitry for transmission and reception.

In Example 22, the subject matter of Example 21 optionally includes, further comprising one or more antennas coupled to the transceiver and a display screen.

Example 23 is a method for configuring a station (STA) to connect to a plurality of access points (APs), the method comprising: sending a request to a first access point (AP) to associate with the first AP to access a network; receiving a service set identifier (SSID), a channel number, an ordered listing of APs for association when traveling in a fast moving scenario, and a plurality of basic service set identifications (BSSIDs) corresponding to the ordered listing of APs; determining whether a signal strength of a second AP exceeds a signal strength of the first AP in the fast moving scenario; and in response to determining that the signal strength of the second AP exceeds the signal strength of the first AP in the fast moving scenario, sending an association request to the second AP to associate with the second AP to access the network using the SSID, the channel number, and a BSSID of the plurality of BSSIDs, the BSSID corresponding to the second AP.

In Example 24, the subject matter of Example 23 optionally includes, wherein the SSID applies to the APs in the ordered listing of APs.

In Example 25, the subject matter of any one or more of Examples 23-24 optionally include, wherein the first AP is a wireless AP operating in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 network.

In Example 26, the subject matter of any one or more of Examples 23-25 optionally include, wherein the first AP is listed first and the second AP is listed second in the ordered listing of APs.

In Example 27, the subject matter of any one or more of Examples 23-26 optionally include, wherein sending the request to the second AP to associate includes sending the request to the second AP to associate without first disconnecting from the first AP.

In Example 28, the subject matter of any one or more of Examples 23-27 optionally include, wherein sending the request to the second AP to associate includes sending the request to the second AP to associate without first sending an authentication request.

In Example 29, the subject matter of Example 28 optionally includes, wherein sending the request to the second AP to associate includes sending the request to the second AP to associate without first receiving an authentication response.

In Example 30, the subject matter of any one or more of Examples 23-29 optionally include, wherein sending the request to the second AP to associate includes sending the request to the second AP to associate without detecting the second AP.

In Example 31, the subject matter of Example 30 optionally includes, wherein sending the request to the second AP to associate without detecting the second AP includes not sending a probe request to the second AP.

In Example 32, the subject matter of Example 31 optionally includes, wherein sending the request to the second AP to associate without detecting the second AP includes not receiving a probe response from the second AP.

In Example 33, the subject matter of any one or more of Examples 23-32 optionally include, wherein the first AP is located at a bus terminal and the ordered listing of APs correspond to a physical arrangement of the APs along a route of a bus starting at a bus terminal.

In Example 34, the subject matter of any one or more of Examples 23-33 optionally include, further comprising receiving a first received signal strength indicator (RSSI) from the first AP and a second RSSI from the second AP; and wherein determining that the signal strength of the second AP exceeds the signal strength of the first AP includes determining that the second RSSI exceeds the first RSSI.

Example 35 is at least one machine-readable medium including instructions for operation of a computing system, which when executed by a machine, cause the machine to perform operations of any of the methods of Examples 23-34.

Example 36 is an apparatus comprising means for performing any of the methods of Examples 23-34.

Example 37 is at least one machine-readable medium including instructions for operation of a computing system, which when executed by a station (STA), cause the STA to: configure a request for transmission to a first access point (AP) to associate with the first AP to access a network; decode a service set identifier (SSID), a channel number, an ordered listing of APs for association when traveling in a fast moving scenario, and a plurality of basic service set identifications (BSSIDs) corresponding to the ordered listing of APs; determine whether a signal strength of a second AP exceeds a signal strength of the first AP in the fast moving scenario; and in response to determining that the signal strength of the second AP exceeds the signal strength of the first AP in the fast moving scenario, configure an association request for transmission to the second AP to associate with the second AP to access the network using the SSID, the channel number, and a BSSID of the plurality of BSSIDs, the BSSID corresponding to the second AP.

In Example 38, the subject matter of Example 37 optionally includes, wherein the SSID applies to all APs in the ordered listing of APs.

In Example 39, the subject matter of any one or more of Examples 37-38 optionally include, wherein the first AP is a wireless AP operating in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 network.

In Example 40, the subject matter of any one or more of Examples 37-39 optionally include, wherein the first AP is listed first and the second AP is listed second in the ordered listing of APs.

In Example 41, the subject matter of any one or more of Examples 37-40 optionally include, wherein to send the request to the second AP to associate includes to send the request to the second AP to associate without first disconnecting from the first AP.

In Example 42, the subject matter of any one or more of Examples 37-41 optionally include, wherein to send the request to the second AP to associate includes to send the request to the second AP to associate without first sending an authentication request.

In Example 43, the subject matter of Example 42 optionally includes, wherein to send the request to the second AP to associate includes to send the request to the second AP to associate without first receiving an authentication response.

In Example 44, the subject matter of any one or more of Examples 37-43 optionally include, wherein to send the request to the second AP to associate includes to send the request to the second AP to associate without detecting the second AP.

In Example 45, the subject matter of Example 44 optionally includes, wherein to send the request to the second AP to associate without detecting the second AP includes to not send a probe request to the second AP.

In Example 46, the subject matter of Example 45 optionally includes, wherein to send the request to the second AP to associate without detecting the second AP includes to not receive a probe response from the second AP.

In Example 47, the subject matter of any one or more of Examples 37-46 optionally include, wherein the instructions further cause the STA to receive a first received signal strength indicator (RSSI) from the first AP and a second RSSI from the second AP; and wherein to determine that the signal strength of the second AP exceeds the signal strength of the first AP includes to determine that the second RSSI exceeds the first RSSI.

In Example 48, the subject matter of any one or more of Examples 13-14 optionally include, wherein the transceiver is to receive the SSID, the channel number, the ordered listing of APs, and the plurality of BSSIDs from the first AP.