Networks of the future will deliver voice and video streams to and from any confine of the network. In particular, multicast video traffic will stretch the network's throughput and delay capabilities and will rely on advanced management of concurrent transmissions to multiple targets. The goals set for multicast video streaming involve managing transmissions to targets on different frequencies or data rates, such as is common in frequency-hopping MACs (media access control) or other cognitive radios. More generally, new communication devices like cell phones include different communication interfaces such as Bluetooth, WiFi, Cellular 3G and 4G networks, GPS (global positioning system), etc.
Systems are built as a combination of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 set of standards for implementing wireless local area network (WLAN) computer communication, the IEEE 802.15.4 standard specifies the physical layer and media access control for low-rate wireless personal area networks (LR-WPANs). The IEEE 802.15.1 standard defines the lower transport layers of the Bluetooth™ wireless technology for wireless personal area networks (WPANs), etc. Other standards in the 802.xx family of standards define other technologies such as ultra wideband, Bluetooth, mesh networks, bridging, mobile broadband wireless access, etc. However, issues at the MAC layer may involve addressing neighbor coverage by different interfaces, concurrent link usage, etc.
Non-homogeneous transceivers that provide the different communication interfaces communicate with different neighbors at different costs and provide a unified layer of abstraction to use interfaces in an efficient manner. Cell phones, personal digital assistants (PDAs), radio systems, etc. may include multiple transceivers whose frequency, connectivity, capacity, throughput, and/or other network metrics has a significant impact on the performance of the network.
The core of frequency assignment is a heuristic for the choice of frequencies for each transceiver. A set of wireless communication transceivers may be assigned frequencies such that data transmission between the two transceivers is possible. The frequencies may be selected from a given set that may differ among transceivers. However, the frequencies assigned to two transceivers may incur interference on one another, resulting in quality loss of the signal. Further, different sets of neighbors may be reachable on different frequencies. Accordingly, more commonality in frequencies is better for connectivity but reduces spatial reuse. Dynamic channel assignment (DCA) schemes are believed to achieve higher system capacity and spectrum efficiency in a frequency-reuse wireless system. However, frequency assignment protocols do not consider the number or state of transceivers at the node itself, or at neighbors or potential neighbors.
a-e illustrate the transitioning of the network configuration shown in
a-e illustrate the transitioning of the network configuration shown in
The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass equivalents of those claims.
A frequency assignment protocol manages transceiver resources in making channel assignment decisions based on the number of assigned (on and ready for communication), unassigned (on but not given a frequency on which to communicate) and inactive (off) transceivers and their evolution over time in order to increase a metric M, which can be connectivity, capacity or any other measurable quantity.
In an idealized network, transceivers would be assigned and unassigned in a way that maximizes a chosen network metric. Unfortunately, this is highly impractical as traffic patterns in the network change quite often over time. These changes cause routes to be recomputed and assignments to be dropped or made frequently. Instead, long-term traffic patterns are captured and decisions are made based on an analysis of the captured long-term traffic patterns. Transceiver managers activate or deactivate transceivers along the data path with a view on long term traffic patterns. Thus, network metrics may be improved along the data path.
A transceiver resource manager (XRM) captures long-term traffic patterns for nodes 110-126. In such an instance, transceivers may need to be activated or deactivated and assigned frequency assignments may need to be modified to increate a selected metric. However, frequency assignment protocols complicate transceiver ramp-up in multicast traffic. For example, a node, such as Node3 116, may have two multicast targets, Node4 118 and Node5 120, and the targets may have two active transceivers, wherein one of the transceivers is assigned as a channel common to all nodes (used to guarantee connectivity at all times). Nodes cannot assign the same frequency or there would only be four (in this case) channels in the network, which does not promote frequency diversity and space reuse. Thus, one of the target nodes may not be able to assign the frequencies used by N0. Thus, XRM may activate or deactivate transceivers, which modifies frequency assignments based on long term traffic patterns to improve network performance along a data path according to the selected metric.
Processing unit 210 may include a processor, microprocessor, or processing logic that may interpret and execute instructions. Processing unit 210 may perform the device data processing functions and other functions of node 200. For example, by way of transceivers 205 node 200 may receive packets for processing and forwarding to subsequent nodes. Processing unit may also implement a transceiver resource manager (XRM) 212 according to an embodiment. Alternatively, XRM 212 may be implemented in a stand-alone device or provided further upstream or downstream from any particular node. For example, the XRM may be provided at a headend in an optical communications system, a mobile switching center in a 2G wireless network, a serving gateway and/or mobility management entity (MME) in a 4G wireless network, e.g., LTE (long term evolution), or other components of a packet-based communications infrastructure. Those skilled in the art will recognize from this description that embodiments are not meant to be confined or limited to the entities mentioned herein, but may depend on the technology implemented or other design decisions.
Memory 215 may provide permanent, semi-permanent, or temporary working storage of data and instructions for use by processing unit 210 in performing device processing functions. Memory 215 may include read only memory (ROM), random access memory (RAM), large-capacity storage devices, such as a magnetic and/or optical recording medium and its corresponding drive, and/or other types of memory devices. Interface 220 may include circuitry for interfacing with a link that connects to a network. Bus 225 may interconnect the various components of node 200 to permit the components to communicate with one another. However, the arrangement of components of device 200 illustrated in
The XRM 212 activates or deactivates transceivers along the data path, with a view on long term traffic patterns. XRM 212 offers a practical way of improving M along the data path, wherein metric M may be connectivity, capacity or any other measurable quantity. XRM 212 includes a frequency assignment device 260. Accordingly, XRM 212 provides a node with the optimal number of transceivers and the most efficient frequency assignments to improve network traffic based on a selected metric. The decisions made by XRM 212 have consequences for frequency assignment in terms of matching the routing tree to data flows and convergence time.
However, if the number or state of transceivers at the node, or at neighbors or potential neighbors, are not considered, frequency assignments may leave a transceivers 205 assigned to frequencies that are not in fact directly useful, thereby leaving the sender with the same number of links to its destinations. XRM 212 handles this frequency assignment (FA) limitation by adding more transceivers in a manner that considers long term traffic patterns.
For example, if the metric M reflects connectivity, FA 260 favors poorly connected neighbors at the time of assigning newly available transceivers. FA 260 selects eligible frequencies that connect to the greatest number of potential neighbors, e.g., nodes that would be neighbors if they shared the same frequency. If, on the other hand, M is a measure of capacity, FA 260 selects eligible frequencies that increase the number of links to previous- and next-hop neighbors. When XRM 212 suggests using fewer transceivers, the order of importance of currently assigned channel is computed in order to preserve the highest level of metric M. In particular, if connectivity is of importance to the network, FA 260 will remove the channel that takes away the smallest number of neighbors.
Data path node2 322 is coupled to node0 310 at the top of the routing tree, and to non-data path node0 360, non-data path node6 362 and to data path node5 364. Data path node2 322 uses 3 transceivers 350, 352, 354. Transceiver 350 uses the second frequency, f1 342, transceiver 352 uses a fourth frequency, f3 380, and transceiver 354 uses a fifth frequency, f4 382. Non-data path node4 360 uses one transceiver 356 and non-data path node6 362 uses one transceiver 458. Transceivers 356, 358 use fourth frequency, f3 380.
Data path node5 364 is coupled to data path node8 366 and data path node9 368. Data path node5 364 uses three 370, 374, 376. Transceiver 370 uses fifth frequency, f4 382, transceiver 374 uses sixth frequency, f5 384, and transceiver 376 uses second frequency, f1 342. Data path node8 366 uses transceivers 378, 390 and data path node9 368 uses transceiver 391. Transceivers 378 uses fifth frequency, f4 382, transceiver 390 uses sixth frequency, f5 384, and transceiver 391 uses second frequency, f1 342
Data path node3 324 is coupled to data path node7 395. Data path node3 324 uses transceivers 392, 393. Transceiver 392 uses third frequency, f2 344 and transceiver 393 uses fourth frequency, f3 380. Data path node7 395 uses three transceivers 394, 396, 397. Transceiver 394 uses fourth frequency, f3 380, transceiver 397 uses first frequency, f0 340, and transceiver 396 uses second frequency, f1 342. Non-data path node10 372 uses two transceivers 397, 398. Transceiver 397 use second frequency, f1 342 and transceiver 398 uses first frequency, f0 340.
The network 300 in
However, as time progresses, the transceiver manager, e.g., XRM 212 as shown in
In
Data path node5 464 is coupled to data path node8 466 and data path node9 468. Data path node5 464 uses four transceivers 470, 472, 474, 476. Transceiver 470 completes the link with node2 422 using fourth frequency, f3 480. Transceiver 472 completes the link with node2 422 using fifth frequency, f4 484. Transceiver 474 uses first frequency, f0 440 to link to node8 466. Transceiver 476 uses second frequency, f1 442 to link to both data path node8 466 and data path node9 468. Transceiver 472 is also used to link to data path node9 468 using fifth frequency, f4 484. Node5 466 is coupled to node5 464 through two links by transceivers 478, 490. Transceivers 478, 490 use first frequency, f0 440, second frequency, f1 442, respectively. Node9 468 uses transceiver 475 to link to node5 464 using fifth frequency, f4 484. Node9 468 also uses transceiver 491 to link to node5 464 using second frequency, f1 442.
Data path node3 424 is coupled to data path node7 495. Data path node3 424 uses transceivers 492, 493 to link to data path node7 495. Transceiver 493 uses fifth frequency, f4 484 and transceiver 489 uses second frequency, f1 442 to link to data path node7 495. Data path node7 495 uses three transceivers 494, 496, 499 to link with non-data path node10 472. Transceiver 494 uses fifth frequency, f4 484, transceiver 499 uses second frequency, f1 442, and transceiver 496 uses second frequency, f1 442. Non-data path node10 498 uses one transceiver 497. Transceiver 497 use second frequency, f1 442 to link with node7 495. By removing the bottlenecks, richer connectivity may be provided by creating an additional link from node0 410 to data path node2 422, an additional link from node2 422 to data path node5 464, an additional link from node5 464 to node9 468 and an additional link from data path node3 424 to data path node7 495.
Accordingly, links to non-data path nodes have been removed and an additional link is created between data path nodes. By requesting non-data path nodes to stop using a transceiver at the non-data path nodes, the data path nodes are able to activate additional, transceivers to use. The additional transceivers at the data path nodes add connectivity between data path nodes which eliminates bottlenecks.
In
Node0 510 now uses four transceivers 530, 532, 534, 536. Transceiver 530 is linked to node5 520, wherein node5 520 includes one transceiver 538. Transceiver 532 is linked with node2 522. Transceiver 534 links to both node2 522 and to node3 524. First frequency, f0 540, is used by transceiver 532 to link to node2 522. Transceiver 530 uses second frequency, f1 542, to link node0 510 to node5 520. However, third frequency, f2 544, is now used by transceiver 534 to link to both node2 522 and to node3 524. Therefore, the bottleneck caused by node5 520 using two transceivers has been eliminated.
Node5 520 includes one transceiver 538 to complete the link with transceiver 530 of node0 510. Node2 522 now uses 3 transceivers, wherein two transceivers 550, 555 are used to link with node0 510. Transceiver 550 uses first frequency, f0 540 and transceiver 553 uses third frequency, f2 544. Node3 524 now uses three transceivers 592, 589, 593, wherein transceiver 589 links to both node0 510 and node7 595 using second frequency, f1 542. Transceiver 592 uses third frequency, f2 544 to complete the link with transceiver 534 of node0 510. Transceiver 593 uses fourth frequency f3 580 to form a link with node7 595. Data path node3 524 also uses transceivers 589 to link to data path node7 595 using second frequency, f1 542.
Non-data path node0 560 is coupled to data path node2 522 using transceiver 556 and second frequency, f1 580. Data path node5 564 is coupled to data path node2 522 through transceiver 570 using second frequency, f1 580. Data path node5 564 is coupled to non-data path node8 566 and non-data path node9 568 through transceiver 576, which uses second frequency, f1 580. Data path node6 562 uses transceiver 558 to complete the link with transceiver 552 using fourth frequency, f3 580. Data path node6 562 also uses transceiver 572 to complete the link with transceiver 550 using first frequency, f0 540. Data path node7 595 is linked to data path node3 524 via transceiver 594 and transceiver 599. Transceiver 599 uses second frequency, f1 542 and transceiver 594 uses fourth frequency, f3 580.
Data path node8 566 uses transceiver 590 to communicate with transceiver 576 on node5 564 using second frequency, f1 542. Data path node9 568 uses transceiver 591 to complete link with transceiver 576 on node5 564 using second frequency, f1 542. Non-data path node10 586 uses one transceivers 598 to complete link with transceiver 599 of node7 595 using second frequency, f1 542.
Accordingly,
The use of two links between node2 522 and node5 564, between node5 564 and node8 566, and between node5 564 and node9 568 have been terminated due to node5 564, node8 566, and node9 568 changing to non-data path nodes.
Now only one link is used between node2 522 and node5 564, between node5 564 and node8 566, and between node5 564 and node9 568.
However, two links are now provided between node2 522 and node6 562 because node6 562 has changed to a data path node.
By freeing unnecessary transceivers on non-data path nodes, energy is conserved, but throughput is increased by reusing available transceivers to increase connectivity between traffic-carrying nodes.
a-e illustrate the transitioning of the network configuration shown in
c shows a transition stage where the link 618 between node0 and node2 has been disassembled. The link 620 between node2 and node5 has also been disassembled. One link 622 between node5 and node8 has also been disassembled. In
a-e illustrate the transitioning of the network configuration shown in
c shows that the second link 718 between node2 and node5 has been terminated thereby leaving only one link between node2 and node5. The second link 720 between node5 and node8 and the second link 722 between node5 and node9 have also been terminated thereby leaving only one link between node5 and node8, and one link between node5 and node9.
For example, if the metric is connectivity, poorly connected neighbors may be favored at the time of assigning available transceivers. Eligible frequencies that connect to the greatest number of potential neighbors, e.g., nodes that would be neighbors if they shared the same frequency, are used. If, on the other hand, the metric is a measure of capacity, eligible frequencies will be selected to increase the number of links to previous and next-hop neighbors. When it is determined that using fewer transceivers is desired, the order of importance of currently assigned channel is computed in order to preserve the highest level of metric. For example, if connectivity is of importance to the network, the channel that takes away the smallest number of neighbors may be removed.
The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments that may be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.
In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are therefore not necessarily meant to indicate order in a series, list or sequence.
The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is to allow the reader to quickly ascertain the nature of the technical disclosure, for example, to comply with 37 C.F.R. §1.72(b). It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. An unclaimed disclosed feature may not be used by any claim. Rather, inventive subject matter may lie in fewer than the features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, wherein a claim stands on its own as a separate embodiment. The scope of the embodiments is to be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
The government owns rights in the present invention pursuant to contract FA8750-11-C-0201, awarded by the Department of the Air Force.