Dynamic bandwidth allocation to transmit a wireless protocol across a code division multiple access (cdma) radio link

IS 2 189 201 T3

DESCRIPTION

Dynamic allocation of bandwidth to transmit a wireless protocol by means of a radio link of a multiple access by division of CDMA codes.

Background of the invention

The increasing use of wireless telephones and personal computers by the general population has led to a corresponding demand for advanced telecommunication services, which at the time were thought to be made only for use in specialized applications.

For example, in the late 1980s, wireless voice communication, such as that available with cellular telephony, had been the exclusive competence of the businessman due to the supposed high subscriber costs. The same was also true for access to remotely distributed computer networks, so that until very recently, only business people and large institutions could afford the necessary computers and wired access equipment.

However, the general population now increasingly wishes not only to have access to networks such as the Internet and private intranets, but also to access such networks, in addition, wirelessly. This is of particular interest to users of portable computers, laptop computers, handheld personal digital assistants and the like, who would prefer to access such networks without being attached to a telephone line.

There is still no widely available satisfactory solution for providing low-cost, high-speed access to the Internet and other networks using existing wireless networks. This situation is most likely a product of several unfortunate circumstances. For example, the topical way of providing high speed data service in the business environment over the wired network is not easily adaptable to the voice quality service available in most homes or offices. Furthermore, such standard high-speed data services do not, in turn, lend themselves well to efficient transmission by standard cellular wireless devices.

Furthermore, the existing cellular network was originally designed only to provide voice services. For the time being, the wireless modulation schemes in use continued their focus on providing voice information, with the maximum data transmission rates being readily available only in the 9.6 kbps range. This is because the cellular switching network in most countries, including the United States, uses analog voice channels that have a bandwidth of approximately 300 to 3,600 hertz. Such a low-frequency channel, in turn, does not directly lend itself to transmitting data at transmission rates of 28.8 kilobits per second (kbps) or even 56.6 kbps, which is now commonly available using inexpensive wireline modems, and Baud rates are now thought of as the minimum acceptable data rates for Internet access.

Switching networks with higher speed building blocks are beginning to be used, at this time, in the United States. Although certain wireline networks, called Integrated Services Digital Networks (ISDNs) capable of higher speed data access have been known for several years, their costs have only recently been reduced to the point where they are attractive to the residential customer, even for wireline service. Although such networks were known at the time cellular systems were originally deployed, for the most part, there is no provision to provide ISDN quality data services over cellular network topologies.

European patent application EP 0 719 062 A2 describes a network architecture and system for providing dynamic bandwidth / channel allocation. In this system, the bandwidth supply is dynamically adjusted according to selected service levels. For example, basic telephone service, wireless ISDN service, wireless data service, wireless multimedia service and other services, such as video broadcasting, are supported in the system by allocating an appropriate number of channels to support each of such services on demand. Summary of the invention

The present invention provides high-speed voice and data service over standard wireless connections through exclusive integration of protocols and existing cellular signaling, such as is available with code-division multiple access-type modulated systems, CDMA (from English, Code Division Multiple Access). The present invention achieves high data transmission speeds through more efficient allocation of access to CDMA wireless channels. In particular, several subchannels are defined within a standard CDMA channel bandwidth, such as assigning different codes for each subchannel. The instantaneous bandwidth needs of each online subscriber unit are met by dynamically allocating multiple subchannels of the RF carrier, on the basis needed for each session. For example, multiple subchannels are granted during times when subscriber bandwidth requirements are relatively high, such as when downloading web pages, and released during times when content on the line is relatively light. such as when the subscriber is reading a web page that has been previously downloaded, or is performing other tasks.

Subchannel allocation algorithms can be implemented to offer various levels of priority service to individual subscribers. AND^or These can be assigned based on available per-subscriber ports, assumed user bandwidth, service premium payments, and so on.

According to another aspect of the invention, some portion of the available bandwidth is initially allocated to establish a communication session. Once the session has been established, if a subscriber unit does not have data to present for transmission, especially,

ES 2 189 201 T3 if the data path remains inactive for some period of time, the previously allocated bandwidth allocation is removed. In addition, it is preferable that the allocation of all previously assigned bandwidth is not removed, but rather at least some portion remains available for use by a subscriber in session. If the inactivity continued for an additional period of time, then even the remaining portion of the bandwidth may be de-allocated from the session. A logical session connection in a network layer protocol remains even if no subchannels are assigned.

In a preferred arrangement, a single subchannel is maintained for a predetermined minimum idle time for each network layer connection. This helps in a more efficient management of channel establishment and dismantling.

Brief description of the drawings

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings, in which similar reference characters refer to them. parts in all different views.

Figure 1 is a block diagram of a wireless communication system that makes use of a bandwidth management scheme according to the invention.

Figure 2 is an Open System Interconnect (OSI) layered protocol diagram showing where the bandwidth management scheme is implemented in terms of communication protocols.

Figure 3 is a diagram showing how subchannels are allocated within a given radio frequency (RF) channel.

Figure 4 is a more detailed block diagram of the elements of a subscriber unit.

Figure 5 is a state diagram of the operations performed by a subscriber unit to dynamically request and release subchannels.

Figure 6 is a block diagram of a portion of a base station unit necessary to service each subscriber unit.

Figure 7 is a high-level structured Spanish description of a process performed by the base station to dynamically manage bandwidth according to the invention. Detailed description of the invention

Turning now to consider the drawings in particular, Figure 1 is a block diagram of a system 100 for providing high-speed voice and data service over a wireless connection by seamlessly integrating a digital data protocol such as, for example, Integrated Services Digital Network (ISDN) with a digitally modulated wireless service, such as Code Division Multiple Access (CDMA).

System 100 consists of two different types of components, including subscriber units 101, 102, and base stations 170. Both types of these components 101 and 170 cooperate to provide the functions necessary to achieve the desired implementation of the invention. The subscriber unit 101 provides wireless data services to a portable computer device 110, such as a portable computer, a personal digital assistant (PDA), or the like. Base station 170 cooperates with subscriber unit 101 to allow data transmission between portable computer device 110 and other devices, such as those connected to the public switched telephone network, PSTN (Public Switched Telephone Network) 180.

More particularly, data and / or voice services are also provided by the subscriber unit 101 to the laptop computer 110, as well as one or more other devices, such as telephones 112-1, 112-2 (collectively referred to herein as telephones). 112). (The telephones 112 themselves may, in turn, be connected to other modems and computers not shown in Figure 1). In the usual ISDN parlance, the portable computer 110 and the telephones 112 are called terminal equipment (TE). The subscriber unit 101 provides the functions called network termination type 1 (NT-1). The illustrated subscriber unit 101 was made, in particular, to work with the so-called ISDN connection of the basic rate interface type, BRI (Basic Rate Interface) that provides two bearer channels or "B" and one uonic. data channel or "D", the usual designation being 2B + D.

The subscriber unit 101 itself consists of an ISDN modem 120, a device referred to herein as the protocol converter 130 that performs the various functions according to the invention, including tampering 132 and bandwidth management 134, a CDMA transceiver 140, and a subscriber unit antenna 150. The various components of the subscriber unit 101 can be realized as discrete devices or as an integrated unit. For example, an existing conventional ISDN modem 120, such as is readily available from various manufacturers, can be used in conjunction with existing CDMA 140 transceivers. In this case, the exclusive functions are entirely provided by the protocol converter 130, which can be sold as a separate device. Alternatively, the ISDN modem 120, protocol converter 130, and CDMA transceiver 140 can be integrated as a complete unit and sold as a single subscriber unit 101 device.

The ISDN modem 120 converts data and voice signals between the terminal equipment 110 and 112 to the format required by the standard ISDN "U" interface. The U interface is a reference point in ISDN systems, which designates a point of connection between the network termination (NT) and the telephone company.

The protocol converter 130 performs spoofing 132 and basic bandwidth management 134 functions, which will be described in more detail below. In general, spoofing 132 consists of ensuring that the subscriber unit 101 appears in the terminal equipment 110, 112, which is

ES 2 189 201 T3 connected to the public switched telephone network 180 on the other side of the base station 170, at all times.

The bandwidth management function 134 is responsible for granting and de-allocating CDMA 160 radio channels, as required. Bandwidth management also includes dynamically managing the bandwidth allocated to a given session, dynamically allocating sub-portions of the CDMA channels 160 in a manner that is fully described below.

The CDMA transceiver 140 accepts the data from the protocol converter 130 and reformats this data appropriately for transmission through a CDMA radio subscriber unit 160-1 antenna 150. The CDMA transceiver 140 may operate on a single 1.25 MHz radio frequency channel alone or, alternatively, in a preferred embodiment, it may be tuned on multiple attributable radio frequency channels.

The CDMA signal transmissions are then received at the base station and processed by the base station equipment 170. The base station equipment 170 typically consists of multichannel antennas 171, multiple CDMA transceivers 172, and a width management functionality 174. band. Bandwidth management controls the allocation of CDMA 160 radio channels and subchannels. The base station 170 then couples the demodulated radio signals to the public switched telephone network (PSTN) 180, in a manner that is well known in the art. For example, base station 170 can communicate with PSTN 180 over any number of different efficient communication protocols, such as mainstream ISDN, or other LAPD-based protocols, such as IS634 or V5.2.

It will also be understood that the data signals travel bi-directionally through the CDMA radio channels 160, that is, the data signals originating from the handheld computer 110 are coupled to the PSTN 180, and the data signals received from the PSTN 180 dock to laptop 110.

Other types of subscriber units, such as unit 102, can be used to provide higher rate data services. Such subscriber units 102 typically provide a service called nB + D type service, which can use the so-called Primary Rate Interface (PRI) protocol to communicate with the terminal equipment. 110, 112. These units provide higher speed service, such as 512 kbps, over the U interface. The operation of the protocol converter 130 and the CDMA transceiver 140 is similar for the nB + D type subscriber unit 102, as discussed above. previously described for subscriber unit 101, with the understanding that the number of radio links 160 to support subscriber unit 102 is greater in number or each has a greater bandwidth.

Turning now to consider Figure 2, the invention can still be described in the context of an open systems interconnection multilayer protocol diagram. The three protocol stacks 220, 230, and 240 are for the ISDN modem 120, the protocol converter 130, and the base station 170, respectively.

The protocol stack 220 used by the ISDN modem 120 is typical for ISDN communications and includes, on the terminal equipment side, analog-to-digital conversion (and digital-to-analog conversion) 221, and formatting 222 of digital data in layer one, and an app layer 223 in layer two. On the U-interface side, the protocol functions include the low-baud rate interface (BRI), as per the 1.430 standard at layer one, a LAPD protocol stack at layer two, such as specified by the standard Q.921 and higher-level network layer protocols, such as Q.931 or X.227, and high-level end-to-end signaling 228 required to establish network-level sessions between modes.

The lower layers of the protocol stack 220 add two bearer channels (B) to achieve a single data rate of 128 kilobits per second (kbps), in a manner that is well known in the art. Similar functionality can be provided on a primary baud rate interface, such as that used by subscriber unit 102, to aggregate multiple B-channels to achieve a data baud rate of up to 512 kbps over the U interface.

Protocol stack 230 associated with protocol converter 130 consists of a layer one low baud rate interface 231 and a layer two LAPD interface 232 on the U interface side, to match the corresponding layers of stack 220 ISDN modem.

In the next higher layer, usually referred to as the network layer, a bandwidth management functionality 235 separates both the U interface side and the CDMA radio link side of the protocol converter stack 230. On the CDMA 160 radio link side, the protocol depends on the type of CDMA radio in use. An efficient wireless protocol, referred to herein as EW [x] 234, encapsulates layer one 231 and layer two 232 ISDN protocol stacks such that terminal equipment 110 can be disconnected from one or more CDMA radio channels. without interrupting a higher network layer session.

Base station 170 contains CDMA 241 and EW [x] 242 equalization protocols, as well as bandwidth management 243. On the PSTN side, the protocols can be converted back to basic baud rate interface 244 and LAPD 245, or higher level network layer protocols such as Q.931 or V5.2 246 can also be included.

The call processing functionality 247 allows the network layer to establish and dismantle channels, and to provide other processing required to support end-to-end session connections between nodes, as is known in the art.

The falsification function 132 performed by

ES 2 189 201 T3 the EW [x] 234 protocol includes the functions necessary to preserve the U interface so that the ISDN connection is properly maintained, even in the absence of a CDMA 160 radio link is available. This is necessary because the ISDN, being a protocol originally developed for wired connections, is supposed to send a continuous stream of synchronous data bits regardless of whether the terminal equipment at either end actually has any data to transmit. Without the spoofing feature 132, radio links 160 of sufficient bandwidth to support at least a 192 kbps data rate will be required for the entire duration of an end-to-end network layer session, if data is actually presented. or not.

Therefore, the EW [x] 234 involves having the CDMA transceiver 140 looping with these synchronous data bits over the ISDN communication path to spoof the terminal equipment 110, 112 in order to make it believe that a link 160 is continuously available. wireless communication device wide enough. However, only when there is data actually present from the terminal equipment to the wireless transceiver 140 is wireless bandwidth allocated. Therefore, unlike the previous technique, the network layer does not have to allocate the allocated wireless bandwidth for the entire communications session. That is, when data is not being presented in the terminal equipment to the network equipment, the bandwidth management function 235 removes the allocation initially assigned to the bandwidth 160 of the radio channel and makes it available for another transceiver and for another subscriber unit 101.

In order to better understand how the 235 and 243 bandwidth management achieves the dynamic allocation of radio bandwidth, now proceed to consider Figure 3. This figure illustrates a possible frequency plan for wireless links 160 following the invention. . In particular, a typical transceiver 170 can be tuned in order to any 1.25 MHz channel within a much larger bandwidth, such as up to 30 MHz. In the case of situation in existing cellular radio frequency bands, these bandwidths are made available, typically, in the range of 800 to 900 MHz. For wireless systems of the type of personal communication systems (PCS), the bandwidth The band is typically allocated in the range from about 1.8 to 2.0 gigahertz (GHz). Furthermore, there are, typically, two simultaneously active equalization bands, separated by a protection band, such as 80 MHz; the two equalizing bands form a full duplex link back and forth.

Each of the CDMA transceivers, such as transceiver 140 in subscriber unit 101 and transceivers 172 in base station 170, are capable of being tuned at any given point in time on a 1.25 MHz radio frequency channel. dice. It is generally understood that such a 1.25 MHz radio frequency carrier provides, at best, a total equivalent of approximately 500 to 600 kbps maximum data rate within acceptable transmission rate limitations of bit error.

In the previous technique, it was generally understood, thus, that in order to support an ISDN-type connection that could contain information at a transmission speed of 128 kbps that, in the best of cases, only approximately subscriber units could be supported. at (500 kbps / 128 kbps) or 3 ISDN only, at best.

In contrast to this, the present invention subdivides the available bandwidth of approximately 500 to 600 kbps into a relatively large number of subchannels. In the illustrated example, the bandwidth is divided into 64 subchannels 300, each providing a data rate of 8 kbps. A given subchannel 300 is phasedly implemented by encoding a transmission with one of several different assignable pseudo-random codes. For example, the 64 subchannels 300 may be defined within a uanic CDMA RF bearer using different orthogonal Walsh codes for each defined subchannel 300.

The basic idea behind the invention is to allocate 300 subchannels only as needed. For example, multiple subchannels 300 are granted during times when a particular ISDN subscriber unit 101 is requesting large amounts of data to be transferred. These subchannels 300 are released during times when the subscriber unit 101 is relatively lightly loaded.

Before describing how the allocation of the subchannels is preferably granted and de-allocated, it will help to understand a typical subscriber unit 101 in greater detail. Turning now to consider FIG. 4, it can be seen that an illustrative protocol converter 130 consists of a microcontroller 410, a backward link processing 420, and a forward link processing 430. The backward link processing 420 further includes ISDN backward forger 422, voice data detector 423, voice decoder 424, data handler 426, and channel multiplexer 428. The forward link processing 430 contains analog functions that operate in the backward direction, including a channel multiplexer 438, a voice data detector 433, a voice decoder 434, a data handler 436, and an ISDN forward forger. 432.

In operation, the backward link 420 first accepts channel data from the ISDN modem 120 over the U interface and forwards it to the backward forger ISDN 422. Any repetitive and redundant bits in "echo" are removed from the data. received and, once retrieved, is sent to the forger 432. Layer three and the remaining higher-level bits are thus information that has to be sent over a wireless link.

This extracted data is sent to speech decoder 424 or data handler 426, depending on the type of data being processed.

IS 2 189 201 T3

Any D-channel data from the ISDN 120 modem is sent directly to discovery

423 of voice data for insertion into the D channel inputs to channel multiplexer 428. The voice data detection circuit 423 determines the content of the D channels by analyzing commands received on the D channel.

The D channel commands can also be interpreted to control a class of wireless services provided. For example, controller 410 may store a customer parameter table containing information about the class of service desired by customers, which may include parameters such as maximum data rate and the like. The appropriate commands are sent to channel multiplexer 428 to request one or more subchannels 300 required by radio links 160 for communication. So, depending on whether the information is voice or data, or the decoder

424 Voice or data handler 426 begins to feed the data inputs to channel multiplexer 428.

Channel multiplexer 428 may also make use of control signals provided by voice data detection circuitry 423, depending on whether the information is voice or data.

In addition, the CPU 410 controller, which operates in conjunction with the channel multiplexer 428, helps to provide the necessary implementation of the EW [x] 234 protocol between the subscriber unit 101 and the base station 170. For example, subchannel requests, or commands Channel establishment and channel dismantling are sent through commands placed on wireless control channel 440. These commands are intercepted by the equivalent functionality in base station 170 to give rise to the appropriate allocation of subchannels 300 to particular network layer sessions.

Data handler 426 provides an estimate of the required data rate for controller CPU 410, so that appropriate commands can be sent on control channel 440 to allocate an appropriate number of subchannels. The data handler 426 can also perform packet mounting and buffering of layer three data, in the appropriate format for transmission.

The forward link 430 operates analogously. In particular, the signals are first received from channels 160 by channel multiplexer 438. In response to information being received on control channels 440, control information is routed to voice data detection circuit 433. Upon determining that the received information contains data, the received bits are routed to the data handler 436. Alternatively, the information is voice information, and routed to the voice decoder 434.

Voice and data information is then sent to the ISDN forward forger 432 for construction in the appropriate ISDN protocol format. This assembly of information is coordinated with the reception of echo bits from the spoiler backwards ISDN 422 to maintain the proper presumed synchronization at the U interface with the ISDN modem 120.

It can now be seen how a network layer communication session can be maintained even though wireless bandwidth initially allocated for transmission is reallocated to other uses when there is no information to transmit. In particular, the backward 422 and forward 432 forgeries cooperate to loop out carrier signals without information, such as flag patterns, sync bits, and other necessary information, in order to tamper with the data terminal equipment connected to the ISDN modem. 120 to continue to function as if the wireless path attributed by the CDMA transceiver 150 was continuously available.

Therefore, unless there is a real need to transmit information from the terminal equipment that is being presented to the channel multiplexers 428, or actual information that is being received from the channel multiplexers 438, the invention may remove the allocation of channels. Initially allocated subchannels 300, making them available to another subscriber unit 101 of the wireless system 100.

The CPU 410 controller can also perform additional functions to implement the EW [x] 234 protocol, including error correction, packet buffering, and bit error rate measurement.

The functions necessary to implement the bandwidth management 235 in the subscriber unit 101 are carried out with respect to the EW [x] protocol, topic by the CPU 410 controller that works in collaboration with the channel multiplexers 428, 438 and data handlers 420, 436. In general, bandwidth allocations are made for each network layer session, based on measured short-term data rate needs. One or more subchannels 300 are then assigned, based on these measurements and other parameters, such as the amount of data queued or the priority of the service as assigned by the service provider. Furthermore, when a given session is idle, a connection is maintained even, preferably end-to-end, albeit assigning a monomeric subchannel number, such as a uonic subchannel. For example, this uonic subchannel can be finally dropped after a predetermined mononymous sleep time is observed.

Fig. 5 is a detailed view of the process by which a subscriber unit 101 can request sub-channel 300 allocations from the base station 170 according to the invention. In a first state 502, the process was in an idle state. At some point, the data is ready to be transmitted and state 504 is entered, in which the fact that the data is ready to be transmitted can be detected by an input data buffer in the data handler 426. , indicated as there are prepared data.

In state 504, a request is made, such as

ES 2 189 201 T3 as through a control channel 440 for the allocation of a subchannel to the subscriber unit 101. If a subchannel is not immediately available, a step state 506 may be entered in which the subscriber unit simply waits and queues its request for a subchannel to be assigned.

Finally, a subchannel 300 is granted by the base station and the process continues to state 508. In this state, the data transfer can then begin using the unique assigned subchannel. The process will continue in this state as long as subchannel 300 is sufficient to maintain the required data transfer and / or is being used. However, if the input buffer becomes empty, as reported by the data handler 426, then the process will proceed to a state 510. In this state 510, the subchannel will remain allocated in the event that it is resume data traffic again. In this case, such as when the input buffer begins to be full once more and the data is ready to be transmitted again, then the process returns to state 508. However, if a low traffic timer expires from state 510, then the process will proceed to state 512 in which subchannel 300 will be released. The process then returns to the idle state 502. In state 512, if a queue request is pending from states 506 or 516, the subchannel is used to satisfy that request, rather than clearing it.

Returning to state 508, if instead of starting to fill the contents of the input buffer at a baud rate that exceeds a predetermined threshold, indicating that subchannel 300 is insufficient to maintain the necessary data flow, then a state 514 is entered in which more subchannels 300 are requested. A subchannel request message is sent again on the control channel 440 or through a subchannel 300 already allocated. If additional subchannels 300 are not immediately available, then a step state 516 can be entered and the request can be tried again by returning to state 514 and 516, as required. Finally, an additional subchannel will be granted and processing can return to 508 state.

With the additional subchannels now available, processing continues to state 518 in which data transfer can be made in an N multiple of the subchannels. This can be done at the same time through a channel link function or other mechanism, to allocate the incoming data between the N subchannels. As the contents of the input buffer are reduced below an empty state threshold, then a wait state 520 can be entered.

If, however, a buffer fill transmission rate is exceeded, then state 514 can be entered, in which more subchannels 300 are requested again.

In state 520, if a high traffic timer has expired, then one or more of the additional subchannels are released in state 522 and the process returns to state 508.

Figure 6 is a block diagram of the components of the base station equipment 170 of the system 100. These components perform functions analogous to those already described in detail in FIG. 4 for subscriber unit 101. It will be understood that one forward link 620 and one backward link 630 are required for each subscriber unit 101 or 102, having to be supported by base station 170.

The base station forward link 620 operates analogously to the forward link 420 in the subscriber unit 100, including an outward multiplexer 622 of subchannels, voice data detection 623, voice decoder 624, data handler 626, and falsifier. ISDN 622, with the understanding that the data is moving in the opposite direction at base station 170. Similarly, the base station outbound link 630 includes components analogous to subscriber forward link 430, including an ISDN spoiler 632, voice data detection 633, voice decoder 634, data handler 636, and multiplexer. 638 of subchannels. The base station 170 also requires a CPU 610 controller.

One difference between the operation of base station 170 and subscriber unit 101 is in the incorporation of bandwidth management functionality 243. AND^and This can be implemented in the CPU 610 controller or another process in the 170 base station.

A high-level description of a computing process, performed by the 650 portion of the dynamic channel allocation of bandwidth management 243, is contained in Figure 7. This process includes a main program 710, which runs continuously, and that includes processing port requests, processing bandwidth release and processing bandwidth requests, and then unused subchannel location and decommissioning.

The processing of port requests is more detailed particularly in a 720 code module. These are included once a port request has been received, and a subchannel reserved for the new connection chosen, preferably from the least used section of the radio frequency bandwidth. Once the reservation is made, an RF channel frequency and code assignment are returned to the subscriber unit 101 and a sub-channel assignment table is updated. Otherwise, if no subchannels are available, then the port request is added to a queue of port requests. An assumed wait time can be estimated on the number of pending port requests and priorities, and an appropriate wait message can be returned to the requesting subscriber unit 101.

In a bandwidth release module 730, the channel bonding function, running in multiplexer 622 on the forward link, is notified of the need to release a subchannel. The frequency and code are then returned to an available set of subchannels.

ES 2 189 201 T3 and a radio recording is updated.

The next bandwidth request module 740 may include selecting the request that has the highest priority with the lowest bandwidth utilization. A list of available subchannels is then analyzed to determine the largest available number. Finally, subchannels are assigned based on need, priority, and availability. A channel bandwidth bonding function is reported within the subchannel multiplexer 622 and the radio recording is updated which maintains which subchannels which connections are assigned.

In the bandwidth-on-demand algorithm, one can typically employ probability theory to manage the number of connections or ports available, and the spectrum needed to maintain the assumed total size and frequency of subchannel assignments. Provisions can also be made for priority service, based on subscribers who have paid a premium for their service.

It should be understood, for example, that in the case of an ISDN subscriber unit 101 supporting 128 kbps, even more than 16 x 8 kbps subchannels can be allocated at any one time. In particular, a larger number, such as 20 subchannels, may be allowed to compensate for delay and reaction when assigning subchannels. This also allows you to deal with data bursts in a more efficient way, such as that typically experienced during web page downloads.

In addition, voice traffic can be prioritized over data traffic. For example, if a voice call is detected, at least one subchannel 300 can be continuously activated, and allocated exclusively to voice handover. This will probably minimize voice call blocking.

Equivalents

While this invention has been particularly shown and described with reference to its preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

For example, instead of ISDN, other digital wired protocols may be encapsulated by the EW [x] protocol, such as xDSL, Ethernet, and X.25, and thus may advantageously use the dynamic wireless subchannel allocation scheme. described in this specification.

Those skilled in the art will recognize or be able to establish, using nothing but routine experimentation, many equivalents to the specific embodiments of the invention specifically described herein. Such equivalents are intended to be encompassed by the scope of the claims.