Patent Publication Number: US-7218644-B1

Title: Dynamic bandwidth allocation for bluetooth access point connections

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention disclosed broadly relates to ubiquitous computing and more particularly relates to improvements in short range RF technology. 
     2. Background Art 
     Bluetooth is a short-range radio network, originally intended as a cable replacement. It can be used to create ad hoc networks of up to eight devices operating together. The Bluetooth Special Interest Group,  Specification Of The Bluetooth System , Volumes 1 and 2, Core and Profiles: Version 1.1, Feb. 22, 2001, describes the principles of Bluetooth device operation and communication protocols. The devices operate in the 2.4 GHz radio band reserved for general use by Industrial, Scientific, and Medical (ISM) applications. Bluetooth devices are designed to find other Bluetooth devices within their ten-meter radio communications range and to discover what services they offer. 
     A connection between two Bluetooth devices is initiated by an inquiring device sending out an inquiry message searching for other devices or access points in its vicinity. Any other Bluetooth device or access point that is listening by means of conducting an inquiry scan, will recognize the inquiry message and respond. The inquiry response is a frequency hop synchronization (FHS) packet containing all of the information required by the inquiring device to address the responding device. This information includes clock value of the sender (i.e., the responding device), the sender&#39;s correct device access code, and the class-of-device (CoD) field. The access code includes the lower address part (LAP) and the upper address part (UAP) of the sender&#39;s Bluetooth Device Address (BD_ADDR), a unique, 48-bit IEEE address that is electronically engraved into each Bluetooth device. 
     The class-of-device (CoD) field of the FHS packet indicates which device class the sender belongs to, such as printer access point, network access point, PDA, cellular telephone, and the like. The class-of-device (CoD) field is a 24 bit field divided into three subfields and a two-bit format field. The high order eleven bit subfield is reserved for indicating general service classes such as information, telephony, audio, object transfer, capturing, rendering, networking, and positioning. The middle five bit subfield comprises the major device class, which can indicate up to 32 different device types. The low order six bit subfield consists is the minor device class, which can indicate up to 64 different variations of each device type. The lowest order two bits are the format field for identifying the format type of the CoD field. 
     The inquiring device will become the master and the responding device will become the slave in the eventual piconet, if a connection is established. To establish a connection, the inquiring device must enter the page state. The inquiring/paging device uses the information provided in the inquiry response packet, to prepare and send a paging message to the responding device. The inquiring/paging device uses the estimated clock CLK and access code of the responding device (i.e., the eventual slave device) to temporarily synchronize with it. Since the inquiring/paging device intends to be the master, it includes an assignment of an active member address (AM_ADDR) in the paging message. The paging message sent by the inquiring/paging device is also a frequency hop synchronization (FHS) packet containing all of the information required by the responding device to directly reply to the inquiring/paging device. This information includes clock value of the sender (i.e., the inquiring/paging device) and the inquiring/paging device&#39;s correct device access code. The responding device must be in the page scan state to allow the inquiring/paging device to connect with it. Once in the page scan state, the responding device will receive the paging packet that provides the clock timing and access code of the inquiring/paging device. The responding device responds with a page acknowledgment packet. This enables the two devices to form a connection and both devices transition into the connection state. The inquiring/paging device that has initiated the connection assumes the role of a master device and the responding device assumes the role of a slave device in a new ad hoc network piconet, using the CLK clock timing and access code of the master device. 
     Each piconet has one master device and up to seven active slave devices. All communication is directed between the master device and each respective slave device. The master initiates an exchange of data and the slave responds to the master. When two slave devices are to communicate with each other, they must do so through the master device. The master device maintains the piconet&#39;s network clock and controls when each slave device can communicate with the master device. Members of the ad hoc network piconet join and leave as they move into and out of the range of the master device. Piconets support distributed activities, such as multi-user gateways to the Internet or to a content server, wherein one device serves as the access point and is connected to an infrastructure network or content server. A user&#39;s device that joins a multi-user gateway piconet, does so to enable its user to access the infrastructure network or content server. 
     Bluetooth access points can deliver approximately 1 Mbps of bandwidth per each Bluetooth module to its client devices. In order to guarantee at least some portion of the bandwidth for each client, some intelligent bandwidth allocation method is required to allow each client device to reserve usable amounts of bandwidth. By preventing connection stalling, bandwidth “exhaustion” is avoided, and more efficient bandwidth allocation is provided. 
     SUMMARY OF THE INVENTION 
     According to an embodiment of the present invention, a system for reapportioning bandwidth for a wireless short-range radio communication link access point is disclosed comprising a short-range radio communication link interface, wherein said interface receives requests from remote devices, and further receives a CoD device class and a minimum bandwidth requirement (Min) for each requesting device; a storage medium, communicatively coupled to the interface, wherein storage medium stores CoD class device and Min values transmitted therewith; and a processor, communicatively coupled to the storage medium, wherein said processor calculates a weighted value for each CoD class device value received, and further initiates redistribution of bandwidth for the bandwidth short-range radio communication link according to the weighted value and Min value. The requests for connection are granted if the sum of all Min values for all requesting devices do not exceed the maximum bandwidth for the short-range radio communication link. Incoming requests for connection are not granted if the sum of all Min values for all previously connected devices, plus the Min value for an incoming request, exceeds the maximum bandwidth for the short-range radio communication link. 
     Under another embodiment, a method is disclosed of reapportioning bandwidth for a wireless short-range radio communication link access point comprising the assignment of a weighted value to each of a plurality of devices connected to the access point; determining a minimum bandwidth requirement for each of the plurality of devices; reapportioning bandwidth among each of the devices according to their minimum bandwidth requirements; and assigning additional bandwidth to each of the devices according to the weighted value. The weighted value is associated with each device&#39;s CoD and device class, and assigning additional bandwidth is repeated each time additional devices are connected to the access point. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  illustrates the bandwidth requirements for various data formats under an embodiment of the invention; 
         FIG. 2  illustrates an embodiment of a Bluetooth device, and the sub-components used under the embodiment; 
         FIG. 3  illustrates a Bluetooth system under an embodiment of the present invention; 
         FIG. 4A  illustrates a connection between a laptop and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4B  illustrates a connection among a laptop, a PDA, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4C  illustrates a connection among a laptop, a PDA, a cellular phone, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4D  illustrates a connection among a laptop, a PDA, a cellular phone, a second laptop, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4E  illustrates a connection among a laptop, a PDA, a cellular phone, a second and third laptop, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4F  illustrates a connection among a laptop, a PDA, a cellular phone, a second, a third, and a rejected fourth laptop, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 4G  illustrates a connection among a laptop, a PDA, a cellular phone, a second, a third, an accepted fourth laptop, and a Bluetooth access point, and further discloses an exemplary bandwidth distribution under an embodiment of the present invention; 
         FIG. 5  is a flowchart illustrating an embodiment of the invention. 
     
    
    
     DISCUSSION OF THE INVENTION 
     In the following description of the various embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. 
     When a Bluetooth connection is made through an access point, a user will typically transmit or receive some type of content through the access point.  FIG. 1  illustrates many of the formats in which a Bluetooth access point will transmit among connected users. Furthermore,  FIG. 1  illustrates the general bandwidth requirements for the listed formats. The “y-axis” of the graph in  FIG. 1  is labeled in terms of a data type, and it&#39;s respective bandwidth requirements, where “speech” is shown near the bottom, thus requiring fewer bandwidth resources. Just above “speech” is the label “Picture/Video,” which would require greater bandwidth resources, while “Data”, labeled towards the top of the y-axis, would require the largest bandwidth requirement. The “x-axis” of the graph of  FIG. 1  labels the bandwidth rates, ranging from zero to over 100 Mbit/s. The values for the illustrated formats ( 101 – 109 ) are given in approximate terms, and may vary slightly from the cited values given, depending on the specific usage. 
     Telephony  101  requires the lowest bandwidth; communication in this format approximately requires just under 0.01 Mbit/s to 0.1 Mbit/s. Next is the Public Radio format  102 , which requires about 0.05 Mbit/s to 3 Mbits/s. The picture/video formats are shown in  FIG. 1  as Video Conference  103 , TV,  104 , and Video  105 . The bandwidth ranges for these formats range from under 0.01 Mbit/s to over 60 Mbit/s. Likewise, data formats Fax  106 , CAD  107 , Pictures  108  and LAN—LAN Communication  109  are shown in  FIG. 1  having bandwidth requirements from under 0.01 Mbit/s to over 100 Mbit/s. It is understood that while formats were described as “Picture/Video” or “Data”, the transmission of related data may include different designations or combinations of this data. 
     The core portion of Bluetooth communication occurs in the protocol stack. The stack allows devices to locate, connect to, and exchange data with each other and to execute interoperable, interactive applications against each other. The elements of the stack are logically partitioned into three main groups: (1) the transport protocol group, (2) the middleware protocol group and (3) the application group. The transport protocol group is composed of the protocols designed to allow devices to locate each other, and to create and configure and manage both physical and logical links that allow higher layer protocols and application to pass data through. The protocols include the radio, baseband, link manager, logical link and adaptation and the host controller interface. The host controller interface defines formats for packets that cross a host interface and associations between these packets. 
     The middleware protocol group contains additional transport protocols to allow existing and new applications to operate over Bluetooth links. The middleware protocol group includes both third-party and industry standard (as well as SIG) protocols developed for Bluetooth wireless communication. The protocols include Internet related protocols, wireless application protocols, object exchange protocols, and the like. Other protocols including RFCOMM, packet-based telephony control, and service discovery protocol are also applicable. 
     The Application group consists of actual applications that make use of Bluetooth links. The applications can include legacy applications that are unaware of Bluetooth transports (e.g., modem dialer application, web browsing client) or they might be aware of Bluetooth wireless communication (e.g., telephony control protocol). Each of these protocols and their configuration are discussed in further detail in Brent A. Miller and Chatschik Bisdikian,  Bluetooth Revealed  (Prentice Hall, 2001) (ISBN 0-13-090294-2). 
       FIG. 2  illustrates a Bluetooth device  200 , and a portion of the baseband and link controller interface as it pertains to other shown portions of the device. Device  200  can be equipped with a keypad  202 , CPU  203  and a cellular radio  204  that communicate over a bus throughout a Bluetooth device  200 . Cellular radio  204  would be found typically in devices such as cell phones. Device  200  is also equipped with storage mediums and other buffers, which are not shown in the figure. The device is also equipped with a Bluetooth radio  209 , which typically operates in the 2.4 GHz industrial, scientific, and medical (ISM) band. 
     Link controller  208  and link manager and host I/O  207  are two important aspects of the Bluetooth baseband  217 . Baseband  217  provides such piconet and device control functions like connection creation, frequency-hopping sequence selection and timing; modes of operation such as power control and secure operation; and medium access functions like polling, packet types, packet processing and link types. Link controller  208  carries out the baseband protocols and other low-level link routines of the Bluetooth system. Link controller  208  uses the baseband to establish network connections, define link packet types and provide error connection. Link controller  208  comprises a number of modules, algorithms and devices, including clock  217 , connection establishment module  218 , frequency hop selection  219 , link type  220  medium access control, power mode and security algorithms  223 . Each of these will be discussed in greater detail below. 
     BD_ADDR  230  represents the Bluetooth device address, and is the most static entity of a Bluetooth device. BD_ADDR  230  is typically a single 48-bit address electronically “engraved” on each device. A device&#39;s BD_ADDR is globally unique among Bluetooth devices. The 48 bit address filed is partitioned typically into three parts: the lower address part (LAP), the upper address part (UAP) and the non-significant address part (NAP). The 24 bits of the UAP and the NAP constitute the organization unique identifier (OUI) part of the address that is assigned by numbering authorities to different organizations. The LAP is assigned internally by various organizations. Various parts of BD_ADDR  230  are involved in most every operation of baseband  217 , including piconet identification, packet header error checking, and authentication and encryption key generation. The device address code (DAC) which is used during paging, is derived from the device BD_ADDR. 
     Clock  217  is typically a free-running 28-bit (native) Bluetooth clock, and runs at a frequency of about 3.2 KHz, which is about twice the nominal frequency hopping rate of 1,600 hops per second. Clock  217  assists in deciding when a device can or cannot transmit or listen for a transmission and at which frequency and for what types of information packets it transmits or listens. A slave device uses the value of the Bluetooth clock of a master to accomplish piconet communication. For example, a Bluetooth channel may be divided into timeslots, each 625 μs in length. The time slots are numbered according to the Bluetooth clock of the piconet master. A scheme may be implemented where a master and slave alternately transmit, wherein the master starts transmission in even-numbered slots only, and the slave starts its transmission in odd-numbered time slots only. The packet start would be aligned with the slot start. Each packet is transmitted on a different hop frequency. A packet nominally covers a single slot, but can be extended to cover up to five slots. 
     Connection Establishment  218  of link controller  208  typically performs a “page” and “inquiry” operation in establishing a Bluetooth connection. Under an embodiment of the invention, one device typically “invites” another device to join its piconet through the use of a page. The device issuing the page is called a paging device, and the device listening (or scanning) for pages is called the paged device. A paging device selects a new frequency at which to transmit a page (e.g. every 312.5 μs). During page scans, when a device listens for transmitted pages, a new listening frequency is selected (e.g., every 1.28 seconds). Typically, a paging device changes frequencies at a much higher rate than a paged device. And while the paged device uses its own clock to drive its frequency selection module (FSM), the paging device uses its best estimate of the clock of the paged device to drive its own FSM. The paging device may estimate the clock value of the paged device based upon the most recent communication between the devices. In the worst case, the paging device could use its own clock. 
     During page operation, a page hopping sequence is typically used. The sequence typically covers 32 unique response frequencies that are in a one-to-one correspondence to a current page hopping sequence (described below). A master and slave may use different rules to obtain the same sequence. The sequence is generated between the paging and paged device by using the 28 least significant bits of the address of the paged device as the address input to a respective frequency selection module (FSM). Further details of specific types of paging sequences are detailed in the Bluetooth Specification. 
     During “inquiry” of connection establishment  218  of link controller  208 , device  200  “searches” for other devices or access points in its vicinity. Just as in paging, an inquiring device selects a new frequency at which to transmit an inquiry (e.g., every 312.5 μs). Inquired devices, executing inquiry scans, select a new listening frequency approximately every 1.28 seconds. Typically, an inquiring device changes frequencies at a much higher rate than an inquired device. Both the inquiring and inquired devices use their own clock (e.g., clock  217  in the case of device  200 ) to driver their FSM&#39;s. During the inquiry operation, an inquiry hopping sequence is used. Each inquiry transmission on a given frequency of the inquiry hopping sequence and each response to it are preceded by an inquiry access code (IAC). Typically there are 64 IAC&#39;s (including a general inquiry access code (GIAC)) associated with 64 reserved lower address parts (LAP). Excluding the GIAC, the remaining 63 IACs are referred to as dedicated IACSs (DIACs). The IAC LAPs will then belong to a set (e.g., 0x0201C, 0x020114, etc.), wherein no device can have an address whose Lap matches any of these reserved LAPs. Further details of inquiry operations are detailed in the Bluetooth specification. 
     It should be noted that while the specification does not define how IACs are to be used, they are intended to be used primarily as a filtering mechanism for identifying well-defined subsets of the devices that may receive inquiries. While all devices that execute inquiry scans generally use the GIAC to generate the inquiry-hopping frequency, only those devices whose receiver correlators are tuned to a particular IAC will receive and respond to inquiries that contain that particular IAC. 
     As mentioned previously, the hopping sequence used within a piconet is determined by the Bluetooth device address of the master (i.e., BD_ADDR) and the phase in the hopping sequence is determined by the Bluetooth clock of the master. In the execution of frequency hop selection  219 , there are 5 general types of hopping sequences defined:
         (1) Page hopping sequence—containing 32 different wake-up frequencies distributed equally with a period (segment) length of 32.   (2) Page response sequence—covers 32 unique response frequencies that are all in a one-to-one correspondence to a current page hopping sequence. The master and slave may be configured to use different rules to obtain the same sequence.   (3) Inquiry sequence—uses 32 unique wake-up frequencies distributed equally with a period (segment) length of 32.   (4) Inquiry response sequence—covers 32 unique response frequencies that are all in an one-to-one correspondence to a current inquiry hopping sequence.   (5) Channel hopping sequence—has a longer period length, and distributes the hop frequencies equally over short periods of time to satisfy the regulatory requirements for the frequency-hopping sequence.       

     Within device  200 , two types of links  220  are typically found: Synchronous Connection-Oriented (SCO) link and Asynchronous Connectionless link (ACL). SCO is a point-to-point link between a master and a single slave in the piconet. The master maintains the SCO link by using reserved slots at regular intervals, and thus can be analogous to a circuit-switched connection between the master and slave. The SCO link typically supports time-bounded information like voice. The ACL link is a point-to-multipoint link between the master and all the slaves participating on the piconet. In the slots not reserved for the SCO link(s), the master can establish an ACL link on a per-slot basis to any slave. It can thus function as a packet-switched connection between the master and all active slaves participating on a piconet. 
       FIG. 2  also discloses the acceptance of asynchronous data  211  and synchronous data  212  or voice. Under an embodiment of the invention, up to three simultaneous synchronous voice channels may be supported. Also, a channel that simultaneously supports asynchronous data and synchronous voice may be utilized. Typically, the asynchronous channel can support an asymmetric link of 723.2 kb/s maximum in either direction, while permitting 57.6 kb/s in the return direction, or a 433.9 kp/s symmetric link. Control lines  210  and  213  provide additional inputs to link controller  208 . 
     Additionally, when device  200  resides on a particular frequency, device  200  may further transmit a baseband packet data unit BB_PDU  214 . BB_PDU  214  is typically a single packetized piece of information, and is strictly constrained within the time device  200  resides at a frequency. However, the resident time at a frequency may also occupy multiple slots, thus permitting multi-slot BB_PDU transmissions to occur. In such a case, a next frequency selected is the one that would have been used if single-slot transmissions had occurred instead. In other words, frequencies from the channel hopping sequence are selected on a slot basis, although the frequency hops themselves occur on a BB_PDU basis. 
     Medium access control  221  includes link control packets including ID, NULL, POLL and FHS packets used in inquiries and pages. Access control  221  performs further processing of packet types and may work in conjunction with BB_PDU to provide indication of signaling or payload-carrying packets. Device  200  is also equipped for different power modes  222  to enable “sleep” modes for device  200 . Security algorithms  223  may also reside in device  200  to provide security between communicating devices, or encoding/encryption on transmitted data or links. 
     Turning to the link manager and host I/O  207 , the link managers exchange messages among external devices communicating with device  200  to control the Bluetooth link among the devices. The communication protocol among link managers is known as the link manager protocol (LMP), and the messages exchanged among communicating link managers are shown as LMP_PDUs  214 . Typically, LMP does not carry application data. Control data  215 ,  216  received at the link manager allows the LMP to either communicate with the link manager in other devices using LMP_PDUs or to send control signals to device  200  baseband  217  and radio layers. 
     Link management  224  further provides security management similar to security algorithms  224  found in link controller  206 ; the security management may provide additional link configuration between devices such as device authentication. The power management feature of link management  224  allows device  200  to regulate and/or reserve power during functionality. Typical power management modes include “sniff”, “hold” and “park.” 
     Quality of service (QoS) management identifies the traffic flow specification for device&#39;s  200  traffic in an outgoing direction over a channel. To allow control of bandwidth assignments of traffic in ACL transmissions, the maximum polling interval for device  200  may be adjusted as needed by a linked master. The adjustment may also be made to provide maximum access delay of ACL BB_PDUs. Typically a master communicating with device  200  can enforce a new maximum poling interval using an LMP_quality_of_service PDU. In such a case, device  200 , acting as a slave, cannot reject this adjustment of the polling interval. Alternately, a request for changing the polling interval via LMP quality_of service_reqI PDU can be accepted or rejected. Both of the LMP_PDUs also contain data specifying the number of times (N BC ) that each broadcast packet is to be repeated. Since this parameter relates to the operation of the entire piconet, N BC  is typically meaningful only when it is transmitted from a master. 
       FIG. 2A  discloses an embodiment of a host controller  253  which interacts with a host and Bluetooth module hardware and firmware. Host controller  253  comprises generally of a host controller interface (HCI) layer  250 , a logical link control and adaptation protocol (L2CAP) layer  251 , and higher layers and applications  252 . HCI layer  250  is supplemented with a series of HCI transport protocols, which are used to transfer HCI data across various physical connections (e.g., USB, RS-232, etc.). HCI  250  contains a command interface to the baseband controller and link manager and access to hardware status. HCI  250  further contains control and event registers. For more detail regarding the specific structures and configurations of the HCI and L2CAP layers, consult the Bluetooth specification. 
     The primary goal of the L2CAP layer  251  is to minimize the involvement of lower-layer transport protocols with the upper layers and applications  252 . This way, many of the developed higher-layer transport protocols and applications may be executed over Bluetooth links with minimum modification. L2CAP  250  deals primarily with ACL-type packets and are referred to as L2CAP_PDUs, and can be carried on ACL BB_PDUs  214  transmissions. L2CAP performs tasks including multiplexing, segmentation and reassembly, as well as group mapping onto networks (i.e., piconets). Additionally, the L2CAP layer  250  further supports the exchange of QoS information. The L2CAP_PDUs may be utilized in connectionless (CL) or connection-oriented (CO) systems. 
       FIG. 3  illustrates an embodiment of the invention showing a Bluetooth routing scheme among mobile terminals (MT)  310 – 315 , fixed masters (FM)  301 – 303  and a master  300  mobile switching center  316 . MSC  316  and associated master  300  keeps track of devices within the system and acts as a relay for routing when required, and is typically joined by fixed connections to fixed masters  317 . The illustrated fixed masters  301 – 303  are typically positioned at fixed intervals throughout an area, and provide interfaces between MSC  316  and other Bluetooth devices (e.g., MTs). MTs  310 – 315  are typical Bluetooth device, communicating and performing tasks in piconets and scatternets throughout the system. 
     Each of the three layers in  FIG. 3  are connected in a way that the MTs are slaves to the FM  317 , wherein the FM  317  is a slave to MSC  316 . FMs  301 – 303  are shown in  FIG. 3  as performing slave functions  304 ,  306 ,  308  to the master  300 , while also serving as master  305 ,  307 ,  309  to the MTs. MTs may also be configured, according to the capability of each MT, to act as slaves to other MTs, illustrated in MTs  310 – 313 . 
       FIG. 4A  discloses an embodiment of the invention, wherein a Bluetooth-enabled device  401  establishes a connection with a Bluetooth access point  400 , illustrated as a fixed master. Under this embodiment, device  401 , shown as a Bluetooth enabled laptop, “inquires” the access point  400 , wherein the master establishes a connection with the devices baseband for communication. Access point  400  may also “page” for connections as well as employ any other Bluetooth profiles in establishing connections (e.g. generic access profile, SDAP, serial port, GOEP, etc.) Once connected, access point  400  records device  401  class of device (CoD) field;  FIG. 4A  shows device  401  having CoD of 0x0201C which identifies the device as “Laptop” under the embodiment. 
     Access point  400  further sets the levels of bandwidth available for connected devices. This is shown in the bar above the table in  FIG. 4A  as having a value from 0 to 921 kbps. Since device  401  is the sole connected device, all of the bandwidth is available for use. However, access point  400  also assigns a weighted value (Wt) to the bandwidth requirement of device  401 , as well as a minimum bandwidth requirement (Min) for the device. The weighted value (Wt) may be automatically assigned for each terminal type, but it may also be some other value that can be used to classify incoming terminals. Bandwidth requirements may also be stored for each designated CoD. Additionally, device BD_ADDRs (or other authentication sources) may impose additional requirements to access point  400 . These values may be set through the implementation of management software in access point  400 . Additional values may be assigned for file types that are to be transmitted (see  FIG. 1 ). In the embodiment shown, device  401  is assigned a Wt of 3, with a minimum bandwidth requirement (Min) of 200 kbps. It is understood that while “minimum” bandwidth rates are discussed in this embodiment, other operative rates may be designated for a device. Thus, a “minimum bandwidth rate” should be interpreted as meaning a rate below which the user does not desire to engage in transmission. The rate can be set by the user, or by the capabilities of the device itself. 
     In  FIG. 4B , a second device  402  is connected to access point  400 . Device  402  is shown having CoD of 0x020114, identifying it as a Palm™ sized PDA. Device  402  has a Wt of 2, with a minimum bandwidth requirement of 100 kbps. Once connected, access point  400  uses the established Min for device  401  and Min for the newly connected device  402  to determine bandwidth allocation. If the available bandwidth exceeds the sum of the Min of devices  401  and  402 , connection for device  402  will be granted. Once granted, access point  400  partitions the bandwidth and calculates the maximum data rate allowable for both devices. In  FIG. 4B , device  401  is assigned a rate of 573 kbps, while device  402  is assigned a data rate of 348 kpb. 
       FIG. 4C  discloses a third device  403  being connected to access point  400 . Device  403  is identified through its CoD 0x420204 as being a cellular phone, with a Wt value of 1, and a minimum bandwidth requirement of 40 kbps. Similar to  FIG. 4B , access point  400  determines whether the maximum bandwidth available exceeds the sum of Min values for devices  401 – 403 . If connection is granted, then each device is calculated a new individual data rate. Next, the appropriate Min worth of bandwidth is assigned for each CoD. Following that, access point  400  proceeds one by one through the devices, with the oldest connection (device  401 ) being first, and assigns additional bandwidth for each CoD class device in accordance with the weighted distribution. The newly connected device is assigned the remainder of the available bandwidth.  FIG. 4C  illustrates the bandwidth distribution as device  401  being assigned 492 kbs, device  402  being assigned 293 kbps, and device  403  getting 136 kbps. 
       FIG. 4D  illustrates a fourth device  404  getting connected to access point  400  (having CoD 0x0201C indicating a laptop). Once again, access point  400  determines whether the maximum bandwidth available exceeds the sum of Min values for devices  401 – 404 . If connection is granted, then each device is calculated a new individual data rate. Next, the appropriate Min worth of bandwidth is assigned for each CoD. Following that, access point  400  proceeds one by one through the devices, with the oldest connection (device  401 ) being first, and assigns additional bandwidth for each CoD class device in accordance with the weighted distribution. The newly connected device is assigned the remainder of the available bandwidth.  FIG. 4D  illustrates the bandwidth distribution as device  401  being assigned 327 kbs, device  402  being assigned 184 kbps, device  403  being assigned 82 kbps, and device  404  getting 328 kbps.  FIG. 4E  illustrates the additional connection of a fifth device  405 , wherein the same process is executed as described above. Accordingly the bandwidth is again reapportioned with device  401  being assigned 245 kbs, device  402  being assigned 130 kbps, device  403  being assigned 55 kbps, device  404  being assigned 245 kbps, and device  405  getting 246 kbps. 
       FIG. 4F  illustrates a case where the presence of device  406  exceeds the capability of access point  400 . As all of the devices shown in  FIG. 4E  remain connected, device  406  attempts to connect to access point  400 . In this embodiment, the sum of the Min values for all devices, including device  406 , now exceed the maximum bandwidth allowed at the access point. In other words, the collective data rate of 940 kbps (sum of Mins for devices  401 – 406 ) is greater than the maximum bandwidth of 921 kbps. In this case, device  406  is denied connection as an incoming terminal, and the remaining devices retain their rates previous to device  406  attempting a connection. 
       FIG. 4G  now illustrates an attempted connection by another device  406 A, except that this time device  406 A has a lower bandwidth requirement (100 kbps). This being the case, the sum of the entire device Min values ( 401 – 406 A) do not exceed the maximum allowable bandwidth (840 kps&lt;921 kbps), and device  406 A is granted a connection. Once a connection is established, each device is calculated a new individual data rate. Next, the appropriate Min worth of bandwidth is assigned for each CoD. Following that, access point  400  proceeds one by one through the devices, with the oldest connection (device  401 ) being first, and assigns additional bandwidth for each CoD class device in accordance with the weighted distribution. The newly connected device is assigned the remainder of the available bandwidth. Accordingly the bandwidth is again reapportioned with device  401  being assigned 218 kbs, device  402  being assigned 111 kbps, device  403  being assigned 45 kbps, device  404  being assigned 218 kbps, device  405  being assigned 218 kbps and device  406 A obtaining the remaining 111 kbps. Thus all of the connected devices will have a workable data rate in their transmissions. 
     It is understood that variations of the preferred embodiment may also be implemented by those skilled in the art to obtain comparable results. While the connections to the access point, and the resulting bandwidth reapportionment, may be obtained on an ad-hoc basis, the use of storage databases may also be used to accelerate the apportionment of bandwidth. For example, a storage database may contain the information shown in the tables of  FIGS. 4A–4G , wherein one database may contain stored CoD values, a second database may contain stored minimum bandwidth requirements, a third database may contained stored addresses, while a fourth may contain Wt values. Numerous combinations of databases may be used in accordance with the requirements of the system. 
     By having a stored database, access point  400  may be able to retrieve data quickly without waiting for a complete transmission of requirements. Address-specific implementations may be employed according to the methods described above to provide customized bandwidth requirements for specific users. Thus, users desiring a higher bandwidth requirement than is specified for the device may transmit that requirement to access point  400  to obtain a unique operative bandwidth requirement. Administrators of the access point may correlate various databases with each other to provide further customization of transmissions through the access point. 
       FIG. 5  is a flowchart illustrating an embodiment of the invention. In step  500 , the Bluetooth access point (BAP) is configured in an initialized mode (i.e., upon startup) or an idle mode. In step  501  the BAP detects whether connections are being made. If no connections exist, the BAP remains in an idle state. However, once a connection is detected, the process moves to step  502 , wherein the BAP determines the CoD and device class of the incoming device. Next, a Min bandwidth rate is established in  503 , and a Wt value is subsequently assigned in  504 . 
     BAP then determines if any other connections are being attempted in step  505 . If no, step  506  determines whether the Min value exceeds the maximum bandwidth available at the BAP (Max). If the requesting device has a Min that exceeds the Max value, the BAP denies the connection in step  507 . If the device requires less bandwidth (i.e., Min&lt;Max) than is provided, the BAP calculates the device Max value in step  508  for the connection. The value is determined similarly to that described above. It is understood that at this point, only one device is connected to the BAP. Additional algorithms may be provided to further allocate bandwidth according to transmitted file types (e.g., video, text, sound, etc.). 
     If step  505  determines that additional connections are being requested, the process moves to step  509 , where the incoming CoD and device class is determined. In steps  510  and  511  the BAP obtains incoming Min bandwidth rate and assigns incoming Wt value for the newly requesting device. In step  512 , the BAP makes a determination of whether the sum of the Mins of all connected devices (Min(sum)) is greater than the maximum allowable bandwidth (Max). If so, the incoming connection request is denied instep  513 . Otherwise, the process continues to step  514 , where the BAP reapportions a Min worth of bandwidth for the connected device(s) as well as the incoming devices. Once the Min for each device is established, step  515  assigns by protocol additional bandwidth according to Wt parameter of each device. It is understood that the protocol may be defined in different ways, (e.g., starting from the oldest connection and proceeding to the newest, proceeding according to CoD, etc). Finally, step  516  assigns the remainder of the available bandwidth to the newly connected device. 
     It is further understood that as additional connections occur at the BAP, the same iterations are performed from steps  509  to  516 . For each incoming device. Once the Min(sum) value exceeds the Max bandwidth for the BAP, the BAP denies all incoming connections until other devices break their connections. 
     Although illustrative embodiments have been described herein in detail, it should be noted and understood that the descriptions and drawings have been provided for purposes of illustration only and that other variations both in form and detail can be made thereupon without departing from the spirit and scope of the invention. The terms and expressions have been used as terms of description and not terms of limitation. There is no limitation to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof.