The invention relates to methods, devices, and systems for defining connection specifications, particularly within a centralized network.
Connection specifications defining connection requirements are needed in a centralized network. A method of effectively and efficiently defining connections in a centralized network is thus highly desirable.
In one aspect of the invention, a method of establishing connections within a centralized network is provided. The method includes the steps of defining a connection specification (CSPEC) based on a CSPEC classification selected from at least one of the following: between a higher layer entity and a lower layer entity; between a first station and a second station; and between a third station and a central coordinator (CCO); requesting a connection associated with the defined CSPEC; and responding with a response indicating whether the requested connection has been granted or rejected. The step of requesting a connection is from at least one of the following: wherein the requesting step is associated with the defined CSPEC based on the CSPEC classification between the higher layer entity and the lower layer entity when the requesting step is between the higher layer entity and the lower layer entity; wherein the requesting step is associated with the defined CSPEC based on the CSPEC classification between the first station and the second station when the requesting step is between the first station and the second station; and wherein the requesting step is associated with the defined CSPEC based on the CSPEC classification between the third station and the CCO when the requesting step is between the third station and the CCO.
In another aspect of the invention, a device is provided. This device is adapted to be operably coupled to a centralized network that applies a connection specification classification based on whether a connection specification (CSPEC) is between a higher layer entity and a lower layer entity, between peer stations, and between a station and a central coordinator. The central coordinator coordinates the network activities. The device includes an admission control module (ACM) and a quality of service monitor module. The ACM is adapted to grant or reject a connection associated with a connection request from one or more stations within the network. This connection request is associated with a CSPEC defined within the centralized network to be applied between peer stations. The quality of service monitor module is operably coupled to the ACM and is adapted to monitor the connection granted by the ACM; gather statistics for the connection granted by the ACM; reconfigure the connection granted by the ACM when one or more violations of the associated CSPEC occur or when the associated CSPEC is modified; and teardown the connection granted by the ACM when the one or more violations of the associated CSPEC occur or when a teardown request of the connection is received
In another aspect of the invention, a central coordinator device is provided. This device is adapted to be operably coupled to a centralized network, which applies a connection specification classification based on whether a connection specification (CSPEC) is between a higher layer entity and a lower layer entity, between peer stations, and between a station and a central coordinator. The central coordinator coordinates the network activities. The device includes a bandwidth scheduling and allocation module, and a beacon configuration and transmission module. The BW scheduling and allocation module is adapted to grant or reject a connection associated with a connection request from one or more stations within the network, wherein the connection request is associated with a CSPEC defined within the centralized network to be applied between a station and a central coordinator; and schedule one or more time intervals for the connection within a contention-free period when the connection is granted. The beacon configuration and transmission module, on the other hand, is operably coupled to the BW scheduling and allocation module and is adapted to define a new beacon, once every beacon period, based on the scheduled one or more time intervals scheduled by the BW scheduling and allocation module; and transmit the defined beacon once every beacon period.
In another aspect of the invention, a system is provided. This system includes a central coordinator (CCO), a first station, and a second station is provided. This system is also a power line communication network. The CCO is operably coupled to the first station and the second station. The CCO is adapted to receive a request for a connection from at least one station, wherein the connection is associated with a connection specification (CSPEC) tailored between the CCO and a station, wherein the at least one station is selected from the group comprising the first station and a second station. The first station is operably coupled to the second station and wherein the first station is adapted to receive a request for a connection from the second station, wherein the connection is associated with a CSPEC tailored between peer stations; and wherein the first station comprises a first higher layer entity and a first lower layer entity adapted to receive a CSPEC tailored between a higher layer entity and a lower layer entity. The second station, on the other hand, is operably coupled to the first station, and wherein the second station is adapted to receive a request for a connection from the first station, wherein the connection is associated with a CSPEC tailored between peer stations; and wherein the second station comprises a second higher layer entity and a second lower layer entity adapted to receive a CSPEC tailored between a higher layer entity and a lower layer entity.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which:
To better understand the figures, reference numerals within the one hundred series, for example, 100 and 118, are initially introduced in
The exemplary network 100, in this embodiment, includes one centralized network (CN). A CN typically includes a central network coordinator also called the central coordinator (CCO) 120 that controls network activities, such as network timing, bandwidth allocation, and security, e.g., authentication and key management. For each centralized network, there is typically one instance of a CCO 120 and zero or more stations 110, 114, 118, 122. In some embodiments, the CCO is the only device initially within the CN. In another exemplary embodiment, the data communication network 100 includes more than one centralized network, with each CN controlled by a CCO. When two or more CNs are available, these CNs may operate, for example, in the coordinated mode.
In some embodiments, the network is a power line communication (PLC) system. Stations 110, 114, 118, 122 that may be connected to this PLC network include devices such as monitors, TVs, VCRs, DVD player/recorders, other audiovisual devices, computers, game consoles, sound systems, information appliances, smart-home technology appliances, home audio equipment, or any other device that is PLC-enabled or compatible, or is able to communicate via the power lines. Although the embodiments of the invention herein are exemplified and discussed using power line networks, features of the present invention are also relevant to other networks; for example, but not limited to, networks, wired or wireless, that have a centralized architecture with a central coordinator controlling the activities of the stations in the network. The use of power line networks in exemplary configurations is intended to aid in understanding the features of the several embodiments of the invention.
In one embodiment of the invention, the network 100 may use time division multiplexing (TDM) as a method of multiple data streams sharing a medium/channel according to time segments. The data streams may be reconstructed according to their time slots. In general, TDM enables several users/stations to share the same frequency by dividing it into different time slots. The stations transmit in rapid succession, one after the other, each using their own defined time slot. Time division multiple access (TDMA) and TDM are techniques known to those of ordinary skill in the art and may be used with PLC technology. The networks of the present invention may also use other time-division multiplexing technology, and other technology such as orthogonal frequency-division or combinations and variations thereof. Other technologies supporting PLC, e.g., orthogonal frequency-division multiplexing (OFDM), however, may also be used within the network and system.
Beacons:
In some embodiments, a CCO 120 manages the activities of stations within its centralized network using, for example, beacons. Beacons are typically control messages that identify the frame configuration and the bandwidth (BW) assignments within a time frame to multiple networks and to stations within a given network. Beacons are typically broadcasted by each CCO, e.g., as a multi-network broadcast, and are decoded by the stations within the network and, in some embodiments by the CCOs of neighbor networks. Beacons are also typically tagged or identified, such that stations within a network decode and follow the BW allocation of its own network beacon and not the beacon of another network. Beacons are also transmitted or broadcasted, typically periodically, into the networks. In some embodiments, they are transmitted unencrypted. In an alternative embodiment, beacons or portions thereof are encrypted.
Beacon Region:
In some embodiments, a beacon region 210 is the region wherein a CCO is able to transmit its own beacon. The beacon region generally includes a plurality of a certain number of beacon or time slots, with the duration of each beacon slot typically sufficient for the transmission of a beacon. In some embodiments, the duration of each beacon slot is equal to the sum of the duration of a beacon PHY protocol data unit (PPDU) and the interframe space. A beacon region 210, in some embodiments, consists of one to a maximum number—typically defined within the system of time slots or beacon slots. In some embodiments, the size of the beacon region, including the number of time slots, may be adjusted dynamically by the CCO. In this exemplary embodiment, the CCO 120 transmits its own beacon at beacon time slot B0212.
Carrier Sense Multiple Access (CSMA) region or Contention Period (CP) Region:
The CSMA region 230 is a region wherein any one or more of many contention access protocols are used to share the medium and to coordinate network traffic. In some embodiments, a CSMA/CA protocol may be used. A network may have one or more CP or CSMA regions. In some embodiments, to be compatible, the CSMA or CP regions of one centralized network do not overlap with the reserved or contention-free period regions of other networks. Communication, however, between two or more interfering networks may be made during overlapping CSMA regions.
For each network, a “minimum CSMA region” (MinCSMARegion) immediately following the beacon region is typically supported. The minimum CSMA region, together with other CSMA regions, located elsewhere in the beacon period, for example, may be used for the following:
The reserved or CFP region 240 is a period when only stations that have explicit authorization from the CCO are allowed to transmit. A reserved region is a time interval that is typically reserved by a network. The network that has been allocated or has acquired control of the reserved region typically schedules the transmission of its contention-free links here. In addition, the CCO may also schedule CSMA allocations that may be used only by the STAs in that network. For example, a time slot 228 in the reserved region 240 has been allocated by the CCO to STA A 110, so that STA A 110 may freely transmit at that time slot or interval 228 without interference, conflict, or contention from other stations 114, 118, 120, 122 within the network. Explained in another way, in that time slot 228, STA A may freely transmit, while other stations in that network are typically silent. This allocation is typically via beacons, such that when a station decodes its own network beacon, information about which station is to use that time slot may also be defined within that beacon. In other embodiments, the CCO sends a message directly to the station informing that station when to transmit and sometimes even listen. A network may have any number of reserved regions in a beacon period.
Stayout Region:
The stayout region 250 is a period within the time frame when all stations assigned a stayout region are instructed by the CCO to remain silent, meaning no transmission. Typically, these stations are also not to use any contention access or contention-free access protocol. A stayout region is assigned to avoid conflicts with a neighboring network that has been assigned a reserved region in the same time interval. In general, a network specifies a stayout region if one or more of the neighboring networks, typically defined for example within a network interfering list, have specified a reserved region or a protected region in the same time interval.
In some embodiments, the various types of regions need not be allocated in one contiguous time interval. This means for example, that the various types of regions may interleave each other, e.g., a time frame or beacon period includes a beacon region, followed by a CSMA region, followed by a stayout region, followed by another CSMA region, and then followed by a reserved region. The various regions within a beacon period may also be of varying sizes with varying number of time slot intervals or durations. In one embodiment, the end time of each region type within a beacon period is stored, for example, in multiples of a defined allocation time unit (e.g., “AllocationTimeUnit”), e.g., 0.32 msec.
In another alternative embodiment, a beacon period may include another region type (not shown) called a Protected Region. When a CCO detects the existence of another group, i.e., another CN or set of CNs with a different timing and if it optionally decides to coordinate with networks in that group, that CCO typically specifies a protected region in the same interval where the beacon region of the other group is located. Stations in a network typically are not allowed to transmit in a protected region. A neighboring group of networks, for example, may have a different beacon period start time.
Based on the beacons transmitted by the CCO, the devices within a network are able to share bandwidth using the same medium or channel, e.g. power line medium. The CCO in each network thus typically controls BW allocation and scheduling within its network. The stations within the network thus decode its own network beacons, and accordingly perform their functions, such as network transmission, following the beacon period allocations or schedule.
Connections and Links:
In some embodiments, the network 100 provides connection-oriented service. A connection may be either unidirectional, i.e., data flows in only one direction, or bidirectional, i.e., data flows in both directions. A forward direction may be defined as the direction from the originating STA to the terminating STA and a reverse direction is the direction from the terminating STA to the originating STA. Explained in another way, a forward link is identified as originating at the STA that initiates the connection-establishment procedure and terminating on the station(s) responding to the connection establishment request. In some embodiments, connections are used to provide guarantees on Quality of Service (QoS). Connection-oriented traffic may use either the CFP or the CP/CSMA, typically depending on the QoS requirements of the connection.
A connection may be composed of links. A link is typically a unidirectional data flow, e.g., a packet or set of related packets, from typically the CL of the source of the link to the CL of one or more destinations of the link. Links may also be categorized as unicast or broadcast/multicast depending on the number of destinations of link. Unicast links typically have a unique destination whereas broadcast/multicast links have multiple destinations. In some embodiments, a connection may be composed of one of the following exemplary combinations of links:
In some embodiments, a distinction between connections and links is made because, at the physical layer, each direction between two stations is likely to have different characteristics and may be allocated separately, if so desired. Furthermore, in some embodiments, different types of links may be supported, e.g., a link controlled by the CCO 120 and those links controlled just by STAs 110, 118, 114, 122.
Typically, every connection and every link has a connection specification (CSPEC) associated with it. A CSPEC typically contains the set of parameters that defines the characteristics and QoS expectations of a connection. Connections may be either unidirectional or bi-directional. For bi-directional connections, a CSPEC is each defined for the forward link and the reverse link. A unidirectional connection may specify only forward or reverse direction QoS requirements, depending on the direction in which the connection's data traffic flows.
Typically, these groupings or classifications are made so as to: (1) maintain QoS information only where it is needed, e.g., in sending/receiving stations, within a station, or in the CCO, etc.; (2) NOT transmit QoS information across the network when the QoS is generally not needed by the receiving device; and (3) localize functions which operate on the QoS or MAC parameters to the particular network entity, e.g., station, peer station, or CCO, i.e., typically more capable of executing such functions. In some embodiments, these groupings or classification enable the more capable entity to address memory usage, protocol signaling, bandwidth usage, and maintenance of QoS level guarantees provided to applications by the network. For example, adjusting bandwidth allocation in time so that application delay QoS parameters is not violated due to changes in channel characteristics is typically done on a fast time scale by the peer stations and not the CCO. The embodiments of the CSPEC of several embodiments of the present invention enable a finer definition and control of connection requirements.
Table I below is an exemplary CSPEC format, with exemplary fields, according to some embodiments of the invention. Other variations in the manner of providing CSPEC information may be implemented and still be in the scope of the invention. For example, additional fields may be added, fields may be deleted, length of fields may be changed, fields may be subdivided into a number of subfields, etc.
The CSPEC may include forward connection information (CINFO), and forward QoS and MAC parameters (QMP)—if the connection includes a forward link, and reverse CINFO and reverse QoS and MAC parameters—if the connection includes a reverse link. In some embodiments, the CINFO, QoS, and MAC parameter fields apply to the forward and/or reverse link, as indicated in the CSPEC. CINFO typically identifies the attributes of the connection and the MAC and protocol adaptation layer (PAL) operations typically required or requested by the connection at the source and destination devices. In some embodiments, the CINFO, QoS, and MAC parameters specifically apply to forward or reverse links, as indicated in the CSPEC. In some embodiments, a separate CINFO is provided for each direction, e.g., one for the forward link and one for the reverse link. Table II below is an exemplary CINFO format, with exemplary fields.
Typically, the QoS parameters of a STA are generated by a connection manager (CM), which in some embodiments are via PAL-specific primitives exchanged between the higher layer applications (HLEs) and the CM and via other connection service functions available.
Each QoS and MAC parameter typically consists of the fields shown in Table III below. Table III shows an exemplary format of QoS and MAC parameters or parameter fields in CSPEC.
The tables shown in this disclosure contain exemplary fields. One of ordinary skill in the art will realize that variations on the fields used, as well as the possible values, are expected and still be within the scope of the invention. Additional fields may be added, as well as removed, and still be in the scope of the present invention.
Exemplary Ordering of Fields with CSPEC:
In some embodiments, the fields within a CSPEC—e.g., those exchanged between CMs and between a CM and a CCO—may be organized in a certain manner. For example, if the CSPEC contains both Forward Link and Reverse Link CSPECs, the Forward Link QMP field(s) are presented before the Reverse Link QMP(s). In some embodiments, within the CSPEC of each link, the QMP fields are arranged in ascending order of the Field Identifier (FID) values. For example, if delay and jitter parameters are both exchanged for the Forward Link between two CMs, the delay bound parameter with FID=“0” appears before the jitter parameter, with FID=“1,” in the Forward Link CSPEC.
Connection Description (CDESC)
The QoS and MAC parameters of the CSPEC exchanged between the HLE and CM (higher layer and lower layer 440), between CMs (STA-to-STA) 450 and between a CM and a CCO (STA-to-CCO) 460 may optionally include a connection descriptor (CDESC). CDESC is a set of fields, which defines the connection to the HLEs, e.g., see Table VII below. The CDESC is typically used by Universal Plug and Play (UPnP) QoS and other HLEs. CDESC is typically used only by the HLE and is usually passed to all involved parties, STAs, including the CCO, thereby enabling the HLE to later construct a list of the active connections without having to query every STA. In some embodiments, there is only at most one CDESC per CSPEC, even if the connection is bidirectional, and the Forward/Reverse field of the corresponding QMP field is typically ignored by the receiving entities.
Vendor-Specific QoS and MAC Parameters
In some embodiments, QMPs of the CSPEC exchanged between the HLE and the CM, between CMs, and between the CM and the CCO may optionally include vendor-specific parameters. Vendor-specific QMP typically has a special Field Identifier (FID) value to identify it as such, e.g., the FID are set to all “1's” that is with a value of “255.” For example, the first three octets of the Body field of this parameter (see Table III) may be an IEEE-assigned Organizationally Unique Identifier (OUI) as exemplified in Table VIII below.
Surplus Bandwidth
In some embodiments, surplus bandwidth (BW), see Table VI, is included as part of the QMP of the CSPEC. A surplus BW field typically indicates the excess amount of BW typically required to support the link relative to the average number of PBs per transmit operation. A value of “00,” for example, may indicate that no surplus BW is required, while a value of “01” may indicate one PB per transmit operation amount of surplus BW is typically required.
In some embodiments, a CCO typically uses surplus BW during the initial admission control procedure. A connection is typically rejected if the average number of PBs per transmit operation along with the requested surplus BW may not be allocated.
Set of QoS and MAC Parameters
In some embodiments, if contention-free service is requested in the MAC Service Type parameter of CINFO, the average data rate, and at least one of delay bound and maximum inter-TXOP time fields are specified between the HLE and the CM. Typically, the receive window size is also defined between a connection CSPEC between two stations, e.g., between two CMs. Moreover, if contention-free service is requested in the MAC service type parameter of CINFO, the connection CSPEC between the STA and the CCO includes the TXOPs per beacon period and the average number of PBs per TXOP fields.
In some embodiment, some CSPEC fields may be modified or reconfigured over the life of the connection. Some exemplary fields that may be reconfigured are shown in Tables II, IV, V, and VI above, indicated by a “Yes” in the last column, i.e., the “Reconfigurable” column. A connection modification request, however, is typically rejected if the reconfigured CSPEC may not be supported.
In some embodiments, a connection is created when the HLE 316 in a given station initiates a messaging sequence to set up the connection. Based on the CSPEC provided by the HLE 316, the CM 802 in this station determines how many links are required and whether each link should be a global link or local link. The CM 802 then communicates with the CM in the destination station (not shown), and possibly with the CCO 120, to establish the one or more links to establish or create the connection. Once the connection is established, the CM 802 is responsible for monitoring the QoS performance of each of its links. If a link is not performing according to its CSPEC, the CM 802 typically initiates a link reconfiguration with a new CSPEC or it may tear down the connection. In some embodiments, it is possible to have several connections between two STAs. In some embodiments, the connection may be between more than two stations. Each of these connections may have either global or local links along with its own, possibly unique, CSPEC.
In some embodiments, global links are established and controlled by the CCO 120 at the request of a CM 802. The source STA and the destination STA, for example, may request sufficient BW from the CCO to guarantee QoS. The CCO typically assigns the global link a dedicated BW allocation and a global link ID (GLID) that is typically unique in a network. In some embodiments, until the CCO assigns the GLID, the global link may be identified by the Connection ID (CID) assigned by the station that initiated the connection. Typically, each connection requested is associated with a CID. In some embodiments, a global link is managed globally by the CCO and locally by the CMs on each of the STAs involved in the connection. A global link may be used in contention-free and contention traffic. A GLID may also be used to identify different types of allocation. For contention-free allocation, for example, the GLID or another field may be used to identify the unique link that may use the medium. For example, identify a local CSMA allocation, a shared CSMA allocation that may be used when the network is operating in a coordinated or compatible mode, identify an allocation used by a designated STA to transmit a beacon, for example, and identify a unique contention-free link in the network.
In some embodiments, local links are used for contention-oriented traffic carried within the contention period. Typically, the CCO is not involved in establishing or controlling local links. The CMs of the STAs typically manages these local links and is responsible for assigning, for example, a local link ID (LLID) to identify the link between the STAs. In some embodiments, local links are used for connection-oriented applications that are not BW demanding, but would like to support, for example, in-order delivery. Packets received may be delivered to the appropriate SAP at the destination STA based on the GLID or LLID, for example.
When a CCO receives a connection-establishment or connection-reconfiguration request from a STA, the admission control module 1030 determines if there is adequate bandwidth to support such request, without compromising the QOS of existing connections. The admission control module 1030 is thus responsible for either accepting or rejecting such requests.
The beacon period configuration and TX module 1020, in some embodiments, defines an appropriate beacon schedule, based on, for example, the scheduling provided by the BW scheduling and allocation module 1010. The beacon may be constructed or updated based on the receipt by the CCO 120 of requests for new links from STAs within the networks, receipt of link reconfiguration requests associated with existing links within the network, and changes to the capacity of existing links as a result of changes to the physical channel. A beacon is typically broadcasted once every beacon period, e.g., showing allocations within a beacon period, by the beacon configuration and TX module 1020 via the I/O interface 926. In some embodiments, the beacon period configuration and TX module 1020 ensures that neighbor centralized networks, for example, a system with two centralized networks and thus two CCOs, are compatible or operating in the coordinated mode. In general, this means, for example, if one CCO allocates a CFP period for one of its STAs in the CN, the other neighbor CCO allocates a stayout region for its STAs in that neighbor network. If one CCO allocates a CSMA period, the neighbor CCO may specify a CSMA or a stayout region or period for the STAs within that neighbor network.
The QoS monitor module 1260 typically monitors and gather statistics for each link. Thus in some embodiments, the QoS monitor module 1260 ensures that the station and the network resources are not over allocated, thereby ensuring the QoS guarantee on accepted/admitted connections. Typically, the admission control module 1250 executes an admission control procedure whenever a new connection, including a new global link, is requested or an existing local connection, including an existing global link, is modified. The QoS monitor module 1260 also typically continuously monitors existing connections, including links, for adherence to the negotiated traffic characteristics (traffic policing) and QoS guarantees.
Violation of the CSPEC parameters, e.g., insufficient BW available, in some embodiments, may cause the QoS monitor module 1260 to reconfigure or tear down an existing connection or global link, which in some embodiments, may depend on the CSPEC's violation policy parameter defined, if any. If a link is torn down, the associated or corresponding connection is typically also torn down.
One of ordinary skill in the art will appreciate that variations on the module of the CCO and the STA are expected. For example, the various modules may be further subdivided into more modules or be incorporated into one main module. Various other divisions and incorporation of functions may also be implemented. The modules in the CCO and the STA also typically interface with each other via the bus.
The CM 1312 on the STA 110 that initiated the connection then sends a CM_CONN_NEW.REQ message 1354 requesting the terminating station(s), in this exemplary embodiment, STA B 118 to add a new connection. This request 1354 typically includes the MAC address of the source or initiating STA, MAC address of the terminating or destination STA, the connection ID identifying the connection being negotiated, and the CSPEC of the new connection. The CSPEC, however, being passed between the two CMs 1312, 1322 is typically the CSPEC exemplified in Table IV above, with additional parameters shown in Table V above.
The CM 1322 at the terminating STA, STA B 118, then informs its associated higher layer HLE 1320 of the requested new connection, e.g., via an APCM_CONN_ADD.IND message 1356. The CSPEC 1356 that is typically passed, with the exemplary APCM_CONN_ADD.IND message, between the CM 1322 and the HLE 1320, however, is the CSPEC that is typically defined between an HLE and a CM as exemplified in Table IV above. Thus, the additional parameters, tailored between two stations, are not necessarily passed between the higher and lower layer entities, e.g., the additional parameters shown in Table V above. The HLE 1320 of the terminating STA then responds, e.g., via an APCM_CONN_ADD.RSP 1358. If the HLE 1320 accepts, the HLE also provides the CM 1322 on the terminating side of the connection the classifier rules that may match the messages in the reverse direction, so the classifier may direct them to the appropriate link. In some embodiments, the HLE 1320 may also send a proposed CSPEC 1358 indicating the CSPEC that the HLE 1320 is currently capable of supporting if the new connection failed. In some embodiments, if a proposed CSPEC is not included with the response 1358, the failure typically is for a reason not related to an inability to support the CSPEC. The response 1358 also typically includes a result code indicating whether the add or new connection request is successful or has failed. The CM 1322 at the terminating STA then sends a CM_CONN_ADD.CNF message 1360 to the CM 1312 of the initiating station, STA A 110, indicating whether the connection request is accepted or rejected. If the negotiation between the CMs is successful to establish a connection or local links between the exemplary two stations, and no global links from the CCO have to be requested, the connection setup or establishment between the two stations 1370 is complete and typically each of the HLEs 1310, 1320 is notified via appropriate confirming messages indicating the connection has been successfully established. After this point 1388, typically the CMs 1312, 1322 may now start exchanging packets belonging to that connection.
If the connection negotiation between the CMs 1312, 1322 is unsuccessful, however, the connection setup is deemed as failed. In the case of broadcast/multicast link, it is possible that some of the destination CMs may have accepted the connection while other have rejected. In this case, the initiating CM typically 1312 sends a CM_CONN_REL.IND message indicating failure of the connection setup to all CMs that accepted the connection and thus the requested connection should appropriately be released. The CMs are also typically responsible for configuring the classifiers to identify packets belonging to links. When a connection setup request was rejected by the CM due to insufficient station resources or rejected by the CCO due to insufficient bandwidth, a proposed CSPEC containing the fields of the CSPEC that may currently be supported may be communicated to the stations belonging to the connection. This enables the application/HLE or the CM to establish a new connection for the streams within the limits of the proposed CSPEC. An HLE may typically request the performance statistics for its connection from the CM, particularly the QoS monitor module 1260, at any time.
Based on the above examples, the CSPEC, typically being passed between the various entities, is dependent on whether the connection request or the connection is between a higher layer entity and a lower layer entity, between at least two stations, and between a station and a CCO. This classification, for example, means that the CSPEC being passed between the higher layer entity and a lower layer entity is different from the CSPEC passed between stations, particularly between their CMs, and is also different from the CSPEC passed between the CM to the CCO. The CSPEC being passed between the two stations is also different from the CSPEC being passed between the station and the CCO. The CSPEC being passed between these three classifications, however, may include redundant information, for example, the CDESC that is used by the HLE, but the CSPEC, however, is considered different, because additional parameters may have been added and/or some parameters have been removed, i.e., the set of parameters defining the CSPEC is different for each classification.
The above figures, particularly
Connection Reconfiguration
In some embodiments, connection reconfiguration may occur when the CSPEC parameters of the connection change. Connection reconfiguration may occur, for example, if an HLE initiates a change in CSPEC for reasons specific to the application or the CM initiates a change in CSPEC when the CM determines that the CSPEC parameters have changed. In general, the connection re-configuration process is similar to the new connection establishment process. Failure to reconfigure a connection, in some embodiments, typically does not cause the existing connection to be dropped.
Acceptance of a connection re-configuration request for connections involving global links typically triggers the CM, particularly the admission and control module (ACM) 1250, to update the local resource allocations to support the modified connections. If the modification or reconfiguration is accepted, the CMs may start transmitting stream based on the new CSPEC. Rejection of the connection modification by CCO may cause the CMs to restore the local resource allocations.
When a connection reconfiguration request is rejected by the CM due to insufficient station resources or by the CCO due to insufficient bandwidth, a proposed CSPEC containing the fields of the CSPEC that may be currently supported is typically communicated to the stations belonging to the connection. This enables the application/HLE or the CM to establish a new connection for the streams within the limits of the proposed CSPEC.
When the HLE determines that the connection needs to be reconfigured, it negotiates with the other station for the reconfiguration, typically involving changes to the CSPEC parameters, and then requests the CM, particularly the ACM 1250, to modify the connection. The CM may also request the CCO for a reconfigured allocation, if the affected link is using the CFP, particularly, if they are global links.
In some embodiments, the CM initiates reconfiguration only when the exception policy in the CSPEC explicitly requires connection reconfiguration under CSPEC violation. If the CM in either station determines that the allocation needs to be reconfigured due to changes to CSPEC, e.g., due to changes in traffic characteristics, the CM typically negotiates directly with the CCO. The CCO may then accordingly notify the stations involved or associated with the connection of the revised allocation.
Although this invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. For example, the exemplary table formats described above may be varied, for example, additional fields added, fields deleted, fields replaced, fields subdivided into subfields, data field types changed, tables subdivided, tables merged, etc. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/703,317 filed Jul. 27, 2005, entitled “Method for Providing Requested Quality of Service,” which is hereby incorporated by reference herein for all purposes.
Number | Date | Country | |
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60703317 | Jul 2005 | US |