Patent Application
20170142638
Embodiments described herein relate generally to an access point for facilitating connection of one or more wireless user devices to a communications channel.
An access point (AP) is a device that provides other user devices, such as PCs, mobile phones, tablet computers, for example, with access to a network such as the internet. The access point may facilitate connection of those user devices to the network by establishing a wireless communications channel between those devices and the access point. When connecting more than one user device to the network, the access point may allocate resources between those user devices; such resources include, for example, the bandwidth of the wireless communications channel, storage memory, battery power etc.
The access point may be configured to operate in a closed access mode, in which the access point only serves devices that have the requisite authorisation, including knowledge of any required encryptions keys. Alternatively, an access point may be configured to operate in an open mode, in which the access point will facilitate connection of any user device to the network, regardless of whether or not the user device in question has access to such keys or other authentication information.
Where access points are deployed arbitrarily in an indoor environment, the limited frequency channel resources available mean that some access points may suffer from excessive aggregated channel interference from neighbouring access points with OBSS (overlapping basic service sets). Access points may also become overloaded with requests for resources from user devices seeking to connect to the network. Together, these factors may result in network congestion and poor service, particularly in the context of high-density Wireless Local Area Networks (VVLANs).
To address the heavy load and OBSS issues, load management schemes have been suggested for allocating user devices to different access points. However, such load management methods are typically based on the premise that the access points will always operate in an open mode; these methods ignore the fact that in any given wireless network, the majority of access points may be privately owned and configured to operate in a closed mode, in which only user devices having the requisite authentication information will be served.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:
According to a first embodiment, there is provided an access point for facilitating connection of one or more wireless user devices to a first communications channel, the access point being operable to allocate resources to user devices seeking to connect to the communications channel, the access point comprising:
a user device authenticator for determining whether a user device connecting to the access point is in possession of pre-determined user device authentication information for obtaining access to the first communications channel;
the access point having first and second modes of operation, wherein in the first mode of operation, the entirety of said resources is available for use by user devices regardless of whether or not the user devices are in possession of the authentication information and in the second mode of operation, the access point is configured to reserve a portion of the resources for user devices that are in possession of the device authentication information;
the access point comprising a mode switching module for switching the mode of operation of the access point, the mode switching module being configured to switch the mode of operation when one or more mode switch criteria are met;
wherein a first one of the mode switch criteria is based on the current demand for resources that the access point is receiving from user devices.
In some embodiments, the access point is operable to establish a wireless communications channel through which the one or more user devices may connect to the access point and achieve access to the first communications channel, wherein the resources include the bandwidth of the wireless communications channel;
wherein in the first mode of operation, the entire bandwidth of the wireless communications channel is available for use by user devices regardless of whether or not the user devices are in possession of the authentication information and in the second mode of operation, the access point is configured to reserve a portion of the bandwidth for user devices that are in possession of the device authentication information;
wherein the first one of the mode switch criteria is based on the current demand for the bandwidth that the access point is receiving from user devices.
In some embodiments, the mode switching module is configured to assess the level of demand from user devices at successive intervals in time.
In some embodiments, when the access point is operating in the first mode and the demand for resources reaches a first threshold during one of the intervals, the mode switching module is configured to immediately switch the access point to the second mode of operation.
In some embodiments, when the access point is operating in the first mode and demand for resources reaches a level below the first threshold but above a second threshold during one of the intervals, the mode switching module is configured to determine whether information for estimating a future level of demand on the access point is available;
wherein in the event that the information is not available, the mode switching module is configured to immediately switch the access point to the second mode of operation.
In some embodiments, in the event that the access point has switched from operating in the first mode to operating in the second mode and the demand for resources subsequently falls below the second threshold during one of the intervals, the access point is configured to switch the access point back to the first mode immediately.
In some embodiments, in the event that the information for estimating a future level of demand is available, the mode switching module is configured to switch the access point to the second mode of operation and to define a maximum period of time for which the access point will remain in the second mode before switching back to the first mode.
In some embodiments, the mode switching module is configured to use the information for estimating the future load to determine whether to switch to the second mode immediately, or to defer switching the access point to the second mode for a predetermined period.
In some embodiments, when the access point is operating in the second mode and demand for resources reaches a first threshold during one of the intervals, the mode switching module is configured to transmit a mode-switch request to a neighbouring access point having corresponding first and second modes of operation, so as to request the neighbouring access point to switch from the second mode to the first mode of operation.
In some embodiments, when the access point is operating in the second mode and the demand for resources remains below a threshold at the end of an interval, the access point is configured to determine if a second mode switch criterion has been met by determining if a mode-switch request has been received from a neighbouring access point in the present interval. In some embodiments, when the access point is operating in the second mode and the demand for resources is above the threshold at the end of the interval, the access point is configured to continue operating in the second mode regardless of whether or not a mode-switch request has been received from a neighbouring access point in the present interval.
In some embodiments, in the event that a mode switch request has been received in the present interval, the mode switching module is configured to determine whether information for estimating a future level of demand is available;
wherein in the event that the information is not available, the mode switching module is configured to immediately switch the access point to the first mode of operation.
In some embodiments, in the event that the information for estimating a future level of demand is available, the mode switching module is configured to use the information to determine whether the access point can switch to the first mode immediately, or whether it should delay switching to the first mode of operation by a predetermined period.
In some embodiments, in the event the access point determines it should delay switching to the first mode of operation, the access point is configured to inform the neighbouring access point of the delay and to await a response from the neighbouring access point, wherein in the event the access point does not receive a positive response from the neighbouring access point within the predetermined period, the access point is configured to remain in the second mode.
In some embodiments, on switching to the first mode, the mode switching module is configured to define a maximum period of time for which the access point will operate in the first mode, before being switched back to the second mode.
In some embodiments, the access point is configured such that, during operation in the second mode of operation, the portion of the resources that is reserved for user devices that are in possession of the device authentication information can be varied.
In some embodiments, when operating in the second mode, the portion of the resources that is reserved for user devices that are in possession of the device authentication information is determined based on the demand for resources from user devices that are connected to the network via the access point and which are in possession of the user device authentication information at the point of switching from the first mode to the second mode.
In some embodiments, the first threshold is variable over time. In some embodiments, the second threshold is variable over time.
The access point 101 may operate in one of two modes: an open mode and a closed mode. When operating in the open mode, a null authentication algorithm is employed by the access point; that is, any user device requesting access to the first communications channel may be authenticated and granted access to the resources by the access point. In contrast, when operating in the closed mode, a portion of the access point's resources is reserved for users that are in possession of predetermined user device authentication information.
The pre-determined user device authentication information may be any type of information that identifies the user device as being entitled to use the reserved portion of the access point's resources. The user device authentication information may comprise a pre-determined data sequence or message that is transmitted from the user device to the access point. For example, the authentication information may comprise a cookie that is transmitted between the user device and the access point. The data sequence may comprise a key for use in a shared key algorithm. The data sequence or message may be transmitted as part of the request to connect to the access point, or in response to a request from the access point.
In some embodiments, the access point may store a list of authorised user devices. Where the access point stores such a list, the authentication information may be information that identifies the user device as one of the list of authorised user devices. For example, the authentication information may be provided as a serial number or other identity label of the user device. The authentication information may comprise a MAC address or IMEI (International Mobile Station Equipment Identity) number of the user device.
A user may obtain the authentication information through payment of a subscription fee to a network service provider that is responsible for maintaining the first communications channel, for example. The subscription may be managed on a fixed term basis e.g. by paying a certain fee for a month or year's subscription, or alternatively in the form of a pay-as-you-go subscription.
Referring still to
The difference between the open and closed modes is shown pictorially in
In one embodiment the portion 201 of the access point's resources that is reserved for recognised user devices will be set as that which is already allocated to recognised user devices at the point in time at which the access point switches from open mode to closed mode. The remaining portion of the resources may then be allocated to the other (unrecognised) user devices that were connected to the access point at the time the access point switched modes. For example, where the resources include the bandwidth of the wireless communication channel between the user devices and the access point, once the access point has switched to closed mode the access point may cease to accept any new connection requests, regardless of whether or not those requests come from recognised user devices. Here, only unrecognised user devices will be allowed access to the “unreserved” portion since by definition, all recognised user devices will have already been allocated the reserved portion of the resources.
In an alternative embodiment, the access point may allow recognised user devices to access the portion of the resources that is not specifically reserved for recognised user devices. The access point may allocate resources to these new recognised user devices at the expense of unrecognised user devices that are currently connected. For example, on switching from open mode to closed mode, the access point may check which ones of the user devices that are currently connected are recognised user devices and which are not by issuing a request to each device to (re)send the authentication information. In the event that a particular user device fails to send the authentication information within a certain period of time, the access point may determine that user device to be an unrecognised device and, depending on the demand for resources from other user devices, may choose to disconnect the user device. Thereafter, the access point will decline any new connection requests from other unrecognised user devices.
When operating in the closed mode, the access point may vary the portion of its resources that is reserved for recognised user devices. Depending on the real-time load status, the resource allocation ratio can be changed at different time periods accordingly; that is, the portion of the resources that is reserved for recognised user devices may be increased or decreased by jointly considering the load on the access point and its neighbouring access points load on a periodic basis. In one example, when operating in the closed mode, the access point may dedicate 10% bandwidth exclusively for recognised user devices in a first interval, then switch to dedicating 50% bandwidth to recognised devices exclusively in a second interval, before switching to reserving 100% of its bandwidth for recognised devices in a third interval. Each access point may use its beacon signals to communicate the load that it is currently experiencing to other neighbouring access points.
It will be understood that, by varying the portion of resources that is reserved for recognised users, the access point does not set an upper limit on the number of recognised devices that can connect to the network; once the reserved portion has been fully allocated to one or more recognised user devices, it is still possible for other recognised user devices to take advantage of the unreserved portion of the access point's resources. User devices that are not recognised will only be able to connect to the network if the access point has spare capacity in the portion of its resources that is not reserved for recognised user devices.
In some embodiments, the access point will be initialised to function in the open mode; that is on powering up, the access point will revert to the open mode by default. Examples of such embodiments will now be described with reference to
Referring to
It is possible that the access point may still switch to the second (closed) mode of operation even if the first mode switch criterion is not met. For example, there may be other mode switch criteria that if satisfied, will prompt the switch from the first (open) mode to the second (closed) mode. As shown in
In the event that the demand on the access point's resources is below the first threshold, the access point proceeds to determine whether or not the demand is above a second threshold that is lower than the first threshold (step S604). If the demand is above the second threshold, the access point determines whether or not information for estimating a future demand on the access point is available (Step S605). For example, the access point may have access to a load database that contains a combination of long-term (weeks+) historical load records and a short-term (e.g. 24 hours) load records, either of which can be used to estimate the likely demand on the access point for the immediate future. The database may be stored locally at the access point, or downloaded from a remote server. If such information is not available, the access point switches to the second (closed) mode (step S603), and again remains in that mode indefinitely, pending a fall in the demand for its resources. If information for estimating the future demand on the access point is available, the access point switches to the second (closed) mode (step S606), but now defines a maximum duration that it will remain in the second (closed) mode before switching back to the first (open) mode—this scenario is discussed further with reference to
Referring back to
Another embodiment will now be described with reference to
It is possible that the access point itself may be experiencing a high level of demand for its resources and may need to request assistance from other, neighbouring access points. In this case, before determining whether the access point has enough capacity to accept a mode switch request from another access point (i.e. before determining if the demand on the access point is above the threshold shown in step S1102 of
The step of determining whether or not the access point can switch to the open mode in an acceptable timeframe (step S1104, S1206) may itself comprise a number of intermediate steps, examples of which are shown in
If the access point determines in step S1303 that it needs to wait a certain amount of time before switching to the open mode, the access point will broadcast a signal, indicating its willingness to switch modes in the future (step S1305). The access point then waits until the relevant amount of time has passed and checks whether it has received notification from the neighbouring access point that the offer to switch modes at this later time has been accepted (steps S1306, S1307). In the event that no such notification has been received in that period, the access point remains in the closed mode, returning to step S1102 (or S1202 of
In some embodiments, when switching from one mode to another, the access point may notify other neighbouring access points of its decision to switch modes. The mode-switch decision can be notified between access points directly by reconfiguring parameters in the access point's beacon frame using overlapping basic service set (OBSS) management. Alternatively, such mode-switch notification can be delivered via associated stations that support the ‘beacon request capability’.
As will be understood from the above, precisely if and when an access point switches from the open mode to the closed mode or vice versa will depend on the current mode in which the access point is operating and the demand on both its resources and those of its neighbouring access points.
While the reader will appreciate that the above embodiments are applicable to any access point used to facilitate the connection of user devices to a wireless network, a typical access point is illustrated in
Usual procedures for the loading of software into memory and the storage of data in the mass storage unit 1703 apply. The processor 1701 also accesses, via bus 1709, a communications unit 1711 that operates to effect communications with the wireless network. Typically, the communications unit 1711 will comprises one or more antennas to act as a transmitter and receiver for establishing a communications link with user devices and/or other nodes in the network.
The communications controller 1707 includes a mode switching module 1713 and a user device authentication module 1715. The mode switching module is operable to select the mode (open/closed) in which the access point is to operate, by implementing steps described above in relation to the various embodiments. Thus, execution of the communications controller software 1707 by the processor 1701 will cause embodiments as described herein to be implemented. When operating in the closed mode, the communications controller is operable to execute the user device authentication module; this module is operable to determine whether a not a user device seeking to connect to the access point is in possession of the pre-determined authentication information and acts to ensure that only recognised user devices obtain access to the reserved portion of the access point's resources.
The communications controller software 1707 can be embedded in original equipment, or can be provided, as a whole or in part, after manufacture. For instance, the communications controller software 1707 can be introduced, as a whole, as a computer program product, which may be in the form of a download, or to be introduced via a computer program storage medium, such as an optical disk. Alternatively, modifications to an existing communications controller 1707 can be made by an update, or plug-in, to provide features of the above described embodiment.
Embodiments can be implemented in a distributed manner without a central control on top of access points or WiFi setup of an extended service set, helping to reduce overall cost. Embodiments can effectively deal with heavy load issues and throughput improvement. The use of one or more thresholds for classifying an access point's load conditions can be used to trigger a switch between operating modes. In this way, an access point can switch its access mode between open mode and closed mode in a spectrum-efficient fashion via periodic load check on its own and neighbouring access points' loads
The schemes described herein can be implemented using existing parameters in IEEE standard 802.11-2012 including IEEE standard 802.11aa-2012. For example, the current load or demand for particular resources that an access point is experiencing can be read from ‘BSS Load’ (order 22) in beacon frame body. (Table 8-20, IEEE standard 802.11-2012). The total number of user stations currently associated with an access point can be found in the ‘Station Count’ field of ‘BSS Load’, for example. Signalling between access points, including the issue and acknowledgement/acceptance of mode-switch requests, can be managed in overlapping BSS (OBSS) management via ‘QLoad Report’ (order 57) and ‘HCCA TXOP Update Count’ (order 58) in beacon frame body (802.11aa-2012).
The objective of OBSS management is to facilitate cooperative sharing of the medium between access points that operate in the same channel and that are able to receive or obtain frames from each other, including Beacon frames. These frames might be received directly or via associated stations that support the ‘beacon request Capability’ (see section 10.11.10, 802.11aa-2012). OBSS management also provides the means to enable the coordination of scheduled transmission opportunity (TXOP) between OBSSs.
OBSS management enables stationary and portable access points to provide to neighbouring access points information for the selection of a channel and for the cooperative sharing of that channel. ‘QLoad report’ in the beacon is the main component of OBSS management is that provides information on:
This information might be used to aid an access point when searching for a channel and also when sharing a channel in an overlap situation.
To coordinate the TXOPs of overlapping ‘hybrid coordination function controlled channel access (HCCA)’ access points, OBSS management provides a means of ‘HCCA TXOP Update Count’ in the beacon for an access point to advertise its TXOP allocations so another access point might schedule its own TXOPs to avoid those already scheduled.
In addition, the following parameters in beacon frame body can be used to facilitate the schemes described herein:
Additional features, such as the load database recording and look-up, instructions to switch mode immediately or defer switching, and instructions to switch back to a previous mode after a predetermined period may be implemented as further orders/parameters in a beacon frame body.
It should be appreciated that while the above embodiments are described with reference to Wireless Local Area Networks, this is by way of example only; access points may provide access to other types of network, e.g. cellular networks, particularly femtocells or small cell systems. Embodiments described herein can be easily implemented to balance the loads among the femtocells, where the femtocells can operate in either closed mode or open mode.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel methods, devices and systems described herein may be embodied in a variety of forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2014/051680 | 6/2/2014 | WO | 00 |
