The present disclosure relates generally to establishing wireless connections to a list of wireless access points.
Taking one specific example, assume that the subway train 100 moves at a speed of 30 meters per second (which is close to 100 kilometers per hour) and the distance between two access points is 90 meters, the reduction of the effective data throughput of the wireless connection depends upon several factors. On average, the subway train 100 will spend about three seconds (i.e., 3 seconds) in the vicinity of each access point. To establish a wireless connection with any given access point, the bridge 150 may first need to scan some or all available channels in order to discover the designated wireless channel for connecting to the given access point; subsequently, the bridge 150 may need to authenticate itself to the given access point and exchange keys with the given access point in order to establish the secured connections. If the bridge 150 spends one second (i.e., 1 second) to discover the designated wireless channel and one second (i.e., 1 second) to establish the secured connections, the bridge 150 may left with only one second (i.e., 1 second) for transferring real data packets with the given access point. In this specific example, for every three seconds available only one second is used for transferring real data packets; thus, the effective data throughput of the wireless connection has been reduced by nearly 66%.
In certain design of wireless networks, it may be desirable to reduce the cell size associated with each access point. As the distance between access points reduces, the effective data throughput of the wireless connection between a computer on a fast moving object (e.g., a subway train, or an automobile) and the wireless networks can be significantly reduced. Therefore, it may be desirable to find some new method to improve the effective data throughput of some wireless connections for those fast moving objects.
In one aspect, the invention is directed to a method of connecting a client on a moving carrier wirelessly to any stationary access point in a list of stationary access points in a predetermined order. The method includes authenticating the client to a first stationary access point in the list of stationary access points. The method includes identifying the client as an authenticated client and informing other access points in the list of stationary access points with respect to the authenticated client. The method includes bypassing an authenticating process when establishing network connections between the authenticated client and one of the other stationary access points.
In another aspect, the invention is directed to a method of connecting a client on a moving carrier wirelessly to any stationary access point in a list of stationary access points in a predetermined order. The method includes finding a designated channel for a next stationary access point from the client's local storage. The method includes monitoring the strength of a radio signal in the designated channel for the next stationary access point while the client is maintaining network connection with a current stationary access point based on a designated channel for the current stationary access point. The method includes terminating network connection between the client and the current stationary access point when the strength of a radio signal in the designated channel for the next stationary access point exceeds the strength of a radio signal in the designated channel for the current stationary access point by a predetermined amount. The method includes establishing and maintaining network connection between the client and the next stationary access point base on the designated channel for the next stationary access point.
In another aspect, the invention is directed to a method of connecting a client on a moving carrier wirelessly to any stationary access point in a list of stationary access points in a predetermined order. The method includes finding from a current stationary access point the designated channel for the next stationary access point. The method includes monitoring the strength of a radio signal in the designated channel for the next stationary access point while the client is maintaining network connection with a current stationary access point based on a designated channel for the current stationary access point. The method includes terminating network connection between the client and the current stationary access point when the strength of a radio signal in the designated channel for the next stationary access point exceeds the strength of a radio signal in the designated channel for the current stationary access point by a predetermined amount. The method includes establishing and maintaining network connection between the client and the next stationary access point base on the designated channel for the next stationary access point.
Implementations of the invention can include one or more of the following advantages. The effective data throughput of some wireless connections between a client on a fast moving carrier and a list of stationary access points can be improved. These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following specification of the invention and a study of the several figures of the drawings.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
The block 310 includes authenticating the client to a first stationary access point in the list of stationary access points. The block 320 includes identifying the client as an authenticated client and informing other access points in the list of stationary access points with respect to the authenticated client. The block 330 includes bypassing an authenticating process when establishing network connections between the authenticated client and one of the other stationary access points. The client can be a bridge 150 as shown in
In one implementation, as the method 300 is exemplarily applied to the system in
In many current systems, when a client (such as the bridge 150) attempt to establish connections with a given access point, the client (such as the bridge 150) generally needs to scan some or all possible channels that can possibly be used to support a particular protocol. For example, the client (such as the bridge 150) may need to scan three channels if the client want establish a connection with the access point using 802.11b protocol. The client may need to scan eight channels if the client want establish a connection with the access point using 802.11a protocol. It is foreseeable that some of the more advanced protocols may use even more channels. It can be very time consuming to scan all possible channels to find the designated channel used by a given access point. Such a problem can only aggravate as the number of all possible channels increases. On the other hand, if the client (such as the bridge 150) knows the designated channel used by a given access point already, the client can monitor the strength of a radio signal in this designated channel, and when the strength of the radio signal in this designated channel exceeds certain threshold, the client can establish the wireless connection with this given access point directly on the designated channel.
In one implementation, as the method 500 is exemplarily applied to the system in
In one implementation, as the block 510 in
In another implementation, the block 510 can include blocks 514 and 516 but does not include block 512. The bridge 150 does not have to learn the designated channel for each access point, for example, by making at least one trip traveling along the railway 400. This information (i.e., the designated channel for each access point) can be provided to the bridge 150 from some other independent source.
Generally, in the foregoing specification and embodiments described, the client can include an access point severing a wireless local area network on the moving carrier. The client can include a bridge operative to connect wirelessly to a stationary access point. The client can include a bridge connecting a local area network on the moving carrier. The client can include a bridge connecting a local area network comprising a wireless local area network on the moving carrier. The client can include a computer. The client can include a telephone implementing voice over internet protocol. The client can include a telephone implementing voice over Wireless LAN protocol.
Generally, in the foregoing specification and embodiments described, the moving carrier can be a subway train, and the list of stationary access points can be arranged along a railway track on which the subway train travels. The moving carrier can be a motor vehicle, and the list of stationary access points can be arranged along a highway on which the motor vehicle travels. The moving carrier can be an elevator, and the list of stationary access points can be arranged along a path near which the elevator moves.
In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.
The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.