Patent Application
20070268127
The above needs are at least partially met through provision of the wireless sensor node data transmission method and apparatus described in the following detailed description, particularly when studied in conjunction with the drawings, wherein:
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.
Generally speaking, pursuant to these various embodiments, a wireless sensor node that is downstream of another wireless sensor node can provide data as corresponds to a sensed condition and which is to be wirelessly transmitted upstream to a collection point via that other wireless sensor node and then determine when to transmit that data as a function, at least in part, of data aggregation opportunities as may exist with respect to that other wireless sensor node. By one approach, a given data aggregation opportunity can comprise, for example, aggregating data regarding a plurality of temporally-differentiated sensed conditions and/or aggregating data from a plurality of wireless sensor nodes (such as, but not limited to, yet another wireless sensor node that is also downstream of the other wireless sensor node).
By one optional approach, if desired, the wireless sensor node can determine when to transmit such data as a function of data aggregation opportunities as are mentioned above as well as quality of service requirements as may otherwise pertain to the data. Relevant quality of service requirements might comprise, but are not limited to, a timeframe within which the data is to be provided to the upstream collection point.
Information regarding data aggregation opportunities can be developed in any of a variety of ways depending upon the limitations and/or capabilities as characterize a given application setting. By one approach, for example, upstream wireless sensor nodes can transmit wireless messages to downstream wireless sensor nodes wherein the messages comprise, at least in part, data aggregation opportunity information.
So configured, sensor data (including but not limited to both locally developed and as may be received from downstream platforms) can be aggregated in an intelligent manner that tends to ensure both conservative use of a given wireless sensor node's transmission facilities and non-sleep time while also tending to ensure the timely delivery of sensor data to ensure that the needs of the governing application remain satisfied. These teachings are readily deployed using existing programmable sensor platforms and hence can be used in conjunction with already-deployed networks. Those skilled in the art will also appreciate that these teachings can be implemented at relatively low cost and can be administered with little additional overhead burden or expense.
These and other benefits may become clearer upon making a thorough review and study of the following detailed description. Referring now to the drawings, and in particular to
It may be noted, however, that such data may be locally obtained (and hence provided) at the wireless sensor node in accordance with some predetermined schedule. For example, it may be important in a given application setting that the data be so provided locally within a first predetermined period of time (such as, for example, once each hour). It may also be that the data as corresponds to a sensed condition is to be provided to the collection point within a second predetermined period of time (such as, for example, once each four hour period), which second period of time is of longer duration than the first predetermined period of time. Other similar examples are of course possible.
This process 100 then provides for determining 102 when to transmit that data to the second wireless sensor node as a function, at least in part, of data aggregation opportunities as may exist with respect to the second wireless sensor node. This can comprise, for example, aggregating data from a single wireless sensor node regarding a plurality of temporally-differentiated sensed conditions (such as, for purposes of illustration, a series of temperature readings that are taken at hourly intervals). This could also comprise, as another example, aggregating data from a plurality of wireless sensor nodes (such as, for purposes of illustration, a temperature reading taken at time X at a first wireless sensor node and another temperature reading taken at that same time X at a second, different wireless sensor node (such as another wireless sensor node that is also downstream of the first wireless sensor node)).
This determination step 102 can further comprise, if desired, determining when to transmit the data to the second wireless sensor node as a function, at least in part, of both the data aggregation opportunities criterion as noted above as well as quality of service requirements that may otherwise pertain to the data. Such an approach may be particularly helpful when the quality of service requirements relate, at least in part, to a timeframe within which the data is to be provided to a collection point that is upstream of the wireless sensor node. As one simple example, the wireless sensor node may be tasked with collecting a temperature reading on an hourly basis but the temporal quality of service requirements for the corresponding application require provision of such sensor data no later than four hours subsequent to its collection. In such a case, one can look for a most favorable data aggregation opportunity as may present itself within that four hour timeframe to thereby achieve both the benefits of data aggregation while also ensuring that an application's quality of service requirements remain met.
There are various ways by which this step of determining 102 when to transmit the data can be partially or fully informed and carried out. By one approach, this step can comprise, at least in part, receiving a wireless message from the upstream second wireless sensor node where that message comprises data aggregation opportunity information. Such information can comprise, for example, transmission schedule information, reception schedule information, available data buffer space, anticipated payload capacity, measured and/or expected best end-to-end delay of forwarded data through a particular upstream second wireless sensor node, membership status with respect to one or more functional groups as correspond to a particular upstream second wireless sensor node, a comparison as between a newly received message from an upstream second wireless sensor node against a similar report (or reports) as corresponds to a different, third wireless sensor node, and/or specific aggregation-based transmission instructions, to note but a few. Such a message can comprise a single transmission/reception event or can comprise a sequence of transmitted/received messages as may best suit the needs and/or opportunities of a given application setting. This can even comprise, for example, ignoring the actual contents of the most recently received message and using only the contents of one or more earlier received messages and the time of arrival of the most recently received message.
Those skilled in the art will appreciate that the above-described processes are readily enabled using any of a wide variety of available and/or readily configured platforms, including partially or wholly programmable platforms as are known in the art or dedicated purpose platforms as may be desired for some applications. Referring now to
In this illustrative embodiment, a wireless sensor node 200 comprises a first memory 201 having data stored therein regarding a sensed condition, which data is to be wirelessly transmitted upstream towards a collection point via a second wireless sensor node and a second memory 202 having locally developed information stored therein regarding when to transmit the data to the second wireless sensor node to dynamically exploit a data aggregation opportunity as exists with respect to the second wireless sensor node. Such data can be provided and/or determined by application of the above-described process 100 if desired.
By one approach, this wireless sensor node 200 also comprises a processor 203 that operably couples to the first and second memory 201 and 202. This processor 203 may be configured and arranged, for example, to determine when to transmit the data to the second wireless sensor node as a function, at least in part, of data aggregation opportunities as may exist with respect to the second wireless sensor node. If desired, this processor 203 can also operably couple to at least a first sensor 204 (and possibly additional sensors as suggested by the illustration presented in
If desired, this wireless sensor node 200 may also comprise a transceiver 205 that operably couples to the processor 203. So configured, the transceiver 205 can serve as a receiver to facilitate and permit compatible reception of wireless messages from, for example, the upstream second wireless sensor node. Such wireless messages can comprise, for example, data aggregation opportunity information as has been previously described. Such a transceiver 205 can also serve as a suitable mechanism by which the sensed condition data is eventually transmitted by the wireless sensor node 200 to the upstream second wireless sensor node.
As described above, if desired, these teachings also provide for taking quality of service requirements into account when determining when to transmit the sensed condition data. To support such an approach, this illustrative embodiment also presents optional inclusion of a third memory 206 that is operably coupled to the processor 203 and that has stored therein information regarding such a quality of service as corresponds to provision of the data to the collection point. Such quality of service information can be relatively static or can, if desired, vary on a more dynamic basis depending upon the needs and requirements of a given application setting.
Those skilled in the art will recognize and understand that such an apparatus 200 may be comprised of a plurality of physically distinct elements as is suggested by the illustration shown in
Referring now to
For purposes of this illustrative example, this network 300 supports an application that needs to receive hourly temperature readings from each of the wireless sensor nodes 302. For quality of service purposes, however, it is not necessary that these temperature readings be received at the data collection point 301 on a corresponding hourly basis. Instead, it is acceptable if such readings are provided within four hours of the data having first been sensed and acquired by each individual wireless sensor node 302.
Accordingly, at a first hour, the first wireless sensor node 305 takes a temperature reading E, the second wireless sensor node 303 takes a temperature reading A, and the third wireless sensor node 304 takes a temperature reading B. In typical ordinary practice, the second and third wireless sensor nodes 303 and 304 would forward their respective temperature readings A and B on to the first wireless sensor node 305 in relatively short order (accounting, of course, for some delay as may be introduced by a need to postpone such a transmission until the end of a current transceiver sleep cycle). By these teachings, however, the second and third wireless sensor nodes 303 and 304 instead consider whether any data aggregation opportunities exist with respect to the first wireless sensor node 305.
In this embodiment the first wireless sensor node 305 transmits a message to the second and third wireless sensor nodes 303 and 304 (using, for example, an already scheduled transmission opportunity) to inform the latter regarding its own buffer capacity and, for example, the number of downstream wireless sensor nodes 302 that it must serve. In this example, the second and third wireless sensor nodes 303 and 304 independently determine that they may defer transmitting their respective temperature readings A and B until they have additional data to transmit as the first wireless sensor node's capacity is sufficient to accommodate such an action and further because such an action will not lead to a violation of the temporal quality of service requirements of the application being served.
Accordingly, an hour later, these wireless sensor nodes 302 again capture a current temperature reading. The downstream wireless sensor nodes 303 and 304 can now determine to transmit that accumulated sensor data as the buffer capacity of the upstream wireless sensor node 305 will not accommodate further sensor data aggregation. Accordingly, the second wireless sensor node 303 transmits its temperature readings A and C while the third wireless sensor node 304 transmits its temperature readings B and D. The first wireless sensor node 305 then aggregates this received sensor reading information with its own temperature readings E and F and transmits that information on to the data collection point 301.
This simple illustration exemplifies that transmissions by the downstream wireless sensor nodes are reduced through dynamic use of aggregation opportunities while simultaneously, if desired, quality of service standards are relate to the gathering of the corresponding data remain satisfied. Those skilled in the art will recognize that this illustrative example represents only a non-exhaustive representation and that numerous other scenarios are both possible and likely.
So configured, sensor data (including but not limited to both locally developed and as may be received from downstream platforms) is dynamically aggregated in an intelligent manner that aids in ensuring conservative use of a given wireless sensor node's transmission facilities and non-sleep time while also aiding to ensure the timely delivery of sensor data to ensure that the needs of the governing application remain satisfied. These teachings are readily deployed using existing programmable sensor platforms and hence can be used in conjunction with already-deployed networks. Those skilled in the art will also appreciate that these teachings can be implemented at relatively low cost and can be administered with little additional overhead burden or expense.
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept. For example, multiple data aggregation opportunities as may exist in a long series of intervening wireless sensor nodes can be taken into account if so desired.
