Abstract:
One embodiment of the present invention provides a computer system that implements a modular access point for clients on a wireless network. This modular access point provides the usual bridging functions to a wired network, such as an Ethernet or a Token Ring. In addition, the modular access point provides other services, such as a printer service, a facsimile service, or a firewall for connecting to a broadband connection. By providing these services within a modular access point, the present invention can reduce cost and can facilitate easier administration at the wireless network.

Description:
BACKGROUND  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to access points for wireless networks. More specifically, the present invention relates to a method and an apparatus for performing services within a modular access point that are normally performed on another network node.  
           [0003]    2. Related Art  
           [0004]    Current computer technology gives the mobile computer user many tools for performing business on the road. These tools include laptop computers and personal organizers. It is often necessary to interface these portable devices to a network in order to communicate with other computing devices and to provide printing and facsimile services. A number of mechanisms have been developed to facilitate this communication, including wireless networking.  
           [0005]    Wireless networking is typically implemented with Radio Frequency (RF) or Infrared (IR) technology so that no physical connection is required with the wired network. In order to access a wireless network, the portable device typically includes an RF or IR transmitter/receiver which communicates with a corresponding transmitter/receiver that is coupled to the wired network. This transmitter/receiver on the wired network is normally contained in an “access point” that performs a conversion from a wireless network protocol to a wired network protocol.  
           [0006]    Current access point technology, whether implemented through dedicated hardware or through software emulation, only performs a bridging function between the wireless network and the wired network. Any peripheral services, such as printing and facsimile transmission, are performed by either dedicated servers on the wired network, or alternatively by clients on the wired network which are configured to provide the peripheral services.  
           [0007]    Providing dedicated servers on the wired network to perform peripheral services is a very costly solution because of duplicated equipment, additional wiring, and additional administration requirements. On the other hand, using clients on the wired network to provide these services places additional load on the clients which can cause the clients to have performance problems.  
           [0008]    What is needed is a modular access point that provides peripheral services in addition to the normal bridging functions of an access point, thereby reducing cost and facilitating easier administration of the wireless network.  
         SUMMARY  
         [0009]    One embodiment of the present invention provides a computer system that implements a modular access point for clients on a wireless network. The modular access point provides the usual bridging functions to a wired network and additionally provides other services to a wireless client. These additional services can include, but are not limited to: a printer service, a facsimile service, and a firewall for connecting to a broadband service such as the Internet.  
           [0010]    In one embodiment of the present invention, the modular access point provides wireless links to wireless clients in accordance with Institute of Electrical and Electronic Engineers (IEEE) connection protocol 802.11.  
           [0011]    In one embodiment of the present invention, the modular access point provides a wired link to wired clients in accordance with an established protocol such as Ethernet or Token Ring.  
           [0012]    In one embodiment of the present invention, the modular access point provides a broadband connection to a network, which may be an Intranet or the Internet.  
           [0013]    In one embodiment of the present invention, the modular access point has an operating system that provides standard operating system services such as a printer service and a facsimile service.  
           [0014]    In one embodiment of the present invention, the modular access point includes an access point controller which controls functions performed by the modular access point.  
           [0015]    In one embodiment of the present invention, the modular access point provides a bridging service to connect the wireless client to the wired network.  
           [0016]    In one embodiment of the present invention, the modular access point provides a firewall between the wireless client and the broadband network.  
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0017]    [0017]FIG. 1 illustrates a modular access point coupling various networks and services together in accordance with an embodiment of the present invention.  
         [0018]    [0018]FIG. 2 is a first portion of a flowchart illustrating the process of routing a Transmission Control Protocol/Internet Protocol (TCP/IP) packet through the system in accordance with an embodiment of the present invention.  
         [0019]    [0019]FIG. 3 is a second portion of the flowchart illustrating the process of routing a TCP/IP packet through the system in accordance with an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]    The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0021]    The data structures and code described in this detailed description are typically stored on a computer readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.  
         [0022]    Computer Systems  
         [0023]    [0023]FIG. 1 illustrates modular access point  104  that communicates with wireless client  100  and wireless client  130  across wireless link  102  and wireless link  132 , respectively. Also illustrated are wired client  124  and wired client  134  that communicate with modular access point  104  across wired network  122 . Network  128  is coupled with modular access point  104  through broadband connection  126 . Modular access point  104  is also coupled to printer  118  and facsimile/modem  120 .  
         [0024]    Modular access point  104 , wireless client  100 , wireless client  130 , wired client  124 , and wired client  134  may include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a personal organizer, a device controller, and a computational engine within an appliance.  
         [0025]    Wireless client  100 , wireless client  130 , wired client  124 , and wired client  134  can include any node on a network including computational capability and including a mechanism for communicating across the network.  
         [0026]    Wired network  122  can include any type of wired communication channel capable of coupling together computing nodes. This includes, but is not limited to, a local area network, a wide area network, or a combination of networks. In one embodiment of the present invention, wired network  122  includes an Ethernet.  
         [0027]    Broadband connection  126  can include any type of broadband access mechanism for communicating with network  128 . This includes, but is not limited to a T1, a T3, or a Frame Relay access mechanism.  
         [0028]    Network  128  can include any type of wire or wireless communication channel capable of coupling together computing nodes. This includes, but is not limited to, a local area network, a wide area network, or a combination of networks. In one embodiment of the present invention, network  128  includes the Internet.  
         [0029]    Modular access point  104  contains an operating system  106  appropriate for the type of computer used to implement modular access point  104 . Operating system  106 , in turn, contains a printer service  108  for accessing printer  118  and a facsimile service  110  for accessing facsimile/modem  120 .  
         [0030]    Access point controller  112  coordinates various operations performed by modular access point  104 . These operations can include: routing network packets among wireless link  102 , wireless link  132 , wired network  122 ; providing a firewall  116  for communications across broadband connection  128 ; and controlling printer service  108  and facsimile service  110  within operating system  106 . Access point controller  112  uses bridging service  114  to perform protocol conversions. In one embodiment of the present invention, access point controller  112  is implemented as a computer program on modular access point  104 .  
         [0031]    Bridging service  114  provides protocol translation between the various client connections. These client connections include, but are not limited to, wireless link  102 , wireless link  132 , wired network  122 , and network  128 . In one embodiment of the present invention, bridging service  114  is implemented as a computer program within modular access point  104 .  
         [0032]    Firewall  116  validates and authorizes access to network  128  across broadband connection  126 . In one embodiment of the present invention, firewall  116  is implemented as a computer program on modular access point  104 .  
         [0033]    Process of Routing a TCP/IP Packet through the System  
         [0034]    [0034]FIG. 2 and FIG. 3 provide a flow chart illustrating the process of routing a TCP/IP packet from wireless client  100  through modular access point  104  to the appropriate destination in accordance with an embodiment of the present invention. The system starts when wireless client  100  generates a TCP/IP packet requesting a service or a connection to another client ( 202 ). This packet is communicated across wireless link  102  to modular access point  104  ( 204 ).  
         [0035]    Access point controller  112  within modular access point  104  inspects the packet header to determine the destination of the packet ( 206 ). If the packets destined for another client on the wireless segment ( 208 ), the packet is sent to the proper destination ( 210 ) across the appropriate wireless link.  
         [0036]    If the packet is not destined for the wireless segment ( 208 ), a test is made to determine if the packet is destined for wired network  122  ( 212 ). If the packet is destined for wired client  124  or wired client  134  on wired network  122 , the packet is passed to bridging service  114  ( 214 ) for possible protocol translation. Bridging service  114  performs any necessary protocol translation and then sends the packet to the destination client across wired network  122  ( 216 ).  
         [0037]    If the packet is not destined for the wired segment ( 212 ), the system determines if the packet is being sent to the broadband segment ( 302 ). If the packet is being sent to the broadband segment, the system further determines if the client is authorized to access the broadband segment ( 304 ). If not, the request is denied ( 322 ) and the requesting client is notified with a message to contact the system administrator.  
         [0038]    If access to the broadband segment is authorized ( 304 ), access point controller  112  opens a port in firewall  116  ( 306 ). Next, access point controller  112  updates its internal routing table with the IP address and port number of the requesting client ( 308 ). The packet is then sent through firewall  116  across broadband connection  126  to network  128  ( 310 ).  
         [0039]    When a return packet is received from network  128  across broadband connection  126 , firewall  116  routes the packet to access point controller  112  ( 312 ). Access point controller  112  examines the packet header and compares the IP address and port number with IP addresses and port numbers in its internal routing table ( 314 ). If a match is found, the packet is passed to the appropriate client on the wireless segment ( 316 ). If the IP address and port number are not found in the internal routing table of access point controller  112  ( 314 ), the packet is dropped ( 324 ) by access point controller  112 .  
         [0040]    If the packet is not destined for the broadband segment ( 302 ), the system determines if the packet includes a request for printer service  108  or facsimile service  110  ( 318 ). If the packet includes a request for printer service  108  or facsimile service  110  ( 318 ), the packet is passed to operating system  106  of modular access point  104  for the appropriate service ( 320 ). If the packet does not include a request for printer service  108  or facsimile service  10  ( 318 ), it is ignored.  
         [0041]    The foregoing descriptions of embodiments of the invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims.