There is a network of ~100 wireless sensors, communicating to a single host. All sensors are located within ~50..100m from the host in the typical urban environment. Ideally, it would be desirable to poll each sensor at least 10 times/sec. When polling the sensors, we have to get just several bits of the status information from each sensor. Problem: as sensors are battery powered, the average power consumption of the entire communication part of a sensor is limited to ~ 10mW max. Is there a wireless technology/modules on the market that would allow such power budget? Would it be possible to develop such technology using existing transceiver ICs or modules? (Cost, operating band, compliance, acceptance, etc. are outside of consideration at this point). Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Feasibility of the VERY low power wireless network?
Started by ●January 5, 2011
Reply by ●January 5, 20112011-01-05
On 1/5/2011 10:09 PM, Vladimir Vassilevsky wrote:> > There is a network of ~100 wireless sensors, communicating to a single > host. All sensors are located within ~50..100m from the host in the > typical urban environment. Ideally, it would be desirable to poll each > sensor at least 10 times/sec. When polling the sensors, we have to get > just several bits of the status information from each sensor. > > Problem: as sensors are battery powered, the average power consumption > of the entire communication part of a sensor is limited to ~ 10mW max. > > Is there a wireless technology/modules on the market that would allow > such power budget? > > Would it be possible to develop such technology using existing > transceiver ICs or modules? > > (Cost, operating band, compliance, acceptance, etc. are outside of > consideration at this point). > > Vladimir Vassilevsky > DSP and Mixed Signal Design Consultant > http://www.abvolt.com >Zigbee?
Reply by ●January 6, 20112011-01-06
On Jan 5, 7:48=A0pm, Mostafa Kassem <m.kassem...@gmail.com> wrote:> On 1/5/2011 10:09 PM, Vladimir Vassilevsky wrote: > > > > > There is a network of ~100 wireless sensors, communicating to a single > > host. All sensors are located within ~50..100m from the host in the > > typical urban environment. Ideally, it would be desirable to poll each > > sensor at least 10 times/sec. When polling the sensors, we have to get > > just several bits of the status information from each sensor. > > > Problem: as sensors are battery powered, the average power consumption > > of the entire communication part of a sensor is limited to ~ 10mW max. > > > Is there a wireless technology/modules on the market that would allow > > such power budget? > > > Would it be possible to develop such technology using existing > > transceiver ICs or modules? > > > (Cost, operating band, compliance, acceptance, etc. are outside of > > consideration at this point). > > > Vladimir Vassilevsky > > DSP and Mixed Signal Design Consultant > >http://www.abvolt.com > > Zigbee?Anything but low power.
Reply by ●January 6, 20112011-01-06
On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote:> > There is a network of ~100 wireless sensors, communicating to a single > host. All sensors are located within ~50..100m from the host in the > typical urban environment. Ideally, it would be desirable to poll each > sensor at least 10 times/sec. When polling the sensors, we have to get > just several bits of the status information from each sensor. > > Problem: as sensors are battery powered, the average power consumption > of the entire communication part of a sensor is limited to ~ 10mW max. > > Is there a wireless technology/modules on the market that would allow > such power budget? > > Would it be possible to develop such technology using existing > transceiver ICs or modules? > > (Cost, operating band, compliance, acceptance, etc. are outside of > consideration at this point). > > Vladimir Vassilevsky > DSP and Mixed Signal Design Consultant > http://www.abvolt.com >What is the real time requirement ? TinyOS maybe what your looking for. A google search for "wireless sensor networks" found this: https://secure.wikimedia.org/wikipedia/en/wiki/Wireless_sensor_network as well as almost 1 million others. hamilton
Reply by ●January 6, 20112011-01-06
On Jan 5, 8:25=A0pm, hamilton <hamil...@nothere.com> wrote:> On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote: > > > > > There is a network of ~100 wireless sensors, communicating to a single > > host. All sensors are located within ~50..100m from the host in the > > typical urban environment. Ideally, it would be desirable to poll each > > sensor at least 10 times/sec. When polling the sensors, we have to get > > just several bits of the status information from each sensor. > > > Problem: as sensors are battery powered, the average power consumption > > of the entire communication part of a sensor is limited to ~ 10mW max. > > > Is there a wireless technology/modules on the market that would allow > > such power budget? > > > Would it be possible to develop such technology using existing > > transceiver ICs or modules? > > > (Cost, operating band, compliance, acceptance, etc. are outside of > > consideration at this point). > > > Vladimir Vassilevsky > > DSP and Mixed Signal Design Consultant > >http://www.abvolt.com > > What is the real time requirement ?OP said 10Hz data.> > TinyOS maybe what your looking for. > > A google search for "wireless sensor networks" found this:https://secure.=wikimedia.org/wikipedia/en/wiki/Wireless_sensor_network> > as well as almost 1 million others.not addressing the real problem. Powering the transmitter constantly will drain any kind of OS/battery.
Reply by ●January 6, 20112011-01-06
hamilton wrote:> On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote: > >> >> There is a network of ~100 wireless sensors, communicating to a single >> host. All sensors are located within ~50..100m from the host in the >> typical urban environment. Ideally, it would be desirable to poll each >> sensor at least 10 times/sec. When polling the sensors, we have to get >> just several bits of the status information from each sensor. >> >> Problem: as sensors are battery powered, the average power consumption >> of the entire communication part of a sensor is limited to ~ 10mW max. >> >> Is there a wireless technology/modules on the market that would allow >> such power budget? >> >> Would it be possible to develop such technology using existing >> transceiver ICs or modules? >> >> (Cost, operating band, compliance, acceptance, etc. are outside of >> consideration at this point). >> >> Vladimir Vassilevsky >> DSP and Mixed Signal Design Consultant >> http://www.abvolt.com >> > What is the real time requirement ? > > TinyOS maybe what your looking for. > > > A google search for "wireless sensor networks" found this: > https://secure.wikimedia.org/wikipedia/en/wiki/Wireless_sensor_network > > as well as almost 1 million others. > > hamiltonIdiot
Reply by ●January 6, 20112011-01-06
On 1/5/2011 9:33 PM, linnix wrote:> On Jan 5, 8:25 pm, hamilton<hamil...@nothere.com> wrote: >> On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote: >> >> >> >>> There is a network of ~100 wireless sensors, communicating to a single >>> host. All sensors are located within ~50..100m from the host in the >>> typical urban environment. Ideally, it would be desirable to poll each >>> sensor at least 10 times/sec. When polling the sensors, we have to get >>> just several bits of the status information from each sensor. >> >>> Problem: as sensors are battery powered, the average power consumption >>> of the entire communication part of a sensor is limited to ~ 10mW max. >> >>> Is there a wireless technology/modules on the market that would allow >>> such power budget? >> >>> Would it be possible to develop such technology using existing >>> transceiver ICs or modules? >> >>> (Cost, operating band, compliance, acceptance, etc. are outside of >>> consideration at this point). >> >>> Vladimir Vassilevsky >>> DSP and Mixed Signal Design Consultant >>> http://www.abvolt.com >> >> What is the real time requirement ? > > OP said 10Hz data. > >> >> TinyOS maybe what your looking for. >> >> A google search for "wireless sensor networks" found this:https://secure.wikimedia.org/wikipedia/en/wiki/Wireless_sensor_network >> >> as well as almost 1 million others. > > not addressing the real problem. > > Powering the transmitter constantly will drain any kind of OS/battery.Some of the links above do target the power issue. My real time question was for data integrity not data speed. If each node sends 10 samples every second, rather than one sample 10 times a second, would that suffice. https://secure.wikimedia.org/wikipedia/en/wiki/Mesh_networking This would help with the overall power, as each node only has to talk with the next node not the remote host. I had the opportunity to work with a water utility manufacture. The remote devices ( water meters ) needed to last 5-8 years in the ground. It used a single 3Volt lithium C-cell. They transmitted a low power signal once every 3 seconds for 100 uSec. This chirp would tell a roving receiver that it was within range. The roving receiver would then ask that meter to dump its entire data (a months worth). The rest of the time it powered down to <10 uA. One of many ideas. hamilton
Reply by ●January 6, 20112011-01-06
On Jan 5, 10:33=A0pm, linnix <m...@linnix.info-for.us> wrote:> On Jan 5, 8:25=A0pm, hamilton <hamil...@nothere.com> wrote: > > > > > On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote: > > > > There is a network of ~100 wireless sensors, communicating to a singl=e> > > host. All sensors are located within ~50..100m from the host in the > > > typical urban environment. Ideally, it would be desirable to poll eac=h> > > sensor at least 10 times/sec. When polling the sensors, we have to ge=t> > > just several bits of the status information from each sensor. > > > > Problem: as sensors are battery powered, the average power consumptio=n> > > of the entire communication part of a sensor is limited to ~ 10mW max=.> > > > Is there a wireless technology/modules on the market that would allow > > > such power budget? > > > > Would it be possible to develop such technology using existing > > > transceiver ICs or modules? > > > > (Cost, operating band, compliance, acceptance, etc. are outside of > > > consideration at this point). > > > > Vladimir Vassilevsky > > > DSP and Mixed Signal Design Consultant > > >http://www.abvolt.com > > > What is the real time requirement ? > > OP said 10Hz data. > > > > > TinyOS maybe what your looking for. > > > A google search for "wireless sensor networks" found this:https://secur=e.wikimedia.org/wikipedia/en/wiki/Wireless_sensor_network> > > as well as almost 1 million others. > > not addressing the real problem. > > Powering the transmitter constantly will drain any kind of OS/battery.yep, only some kinda high-powered RFID/'toll-tag' approach where the sensor is powered by the interrogating signal or solar powered/backed- up sensors ???? and 'sorting'/ID'ing the responses could get tricky i suppose. Maybe use cellphone or other radio technology (ultrasonic burst?) to 'wake'/enable the sensors in an 'area', then shut them off and move on?
Reply by ●January 6, 20112011-01-06
In article <J-SdnVz2Csvyr7jQnZ2dnUVZ_jqdnZ2d@giganews.com>, nospam@nowhere.com says...> > There is a network of ~100 wireless sensors, communicating to a single > host. All sensors are located within ~50..100m from the host in the > typical urban environment. Ideally, it would be desirable to poll each > sensor at least 10 times/sec. When polling the sensors, we have to get > just several bits of the status information from each sensor.100 sensors at 10Hz means 1,000 samples per second. If they occupy the same bandwith, each sensor has to power up, sync, and transmit in 1mSec. If it is really a polled network, you have to subtract from the millisecond, the time for the polling signal.> > Problem: as sensors are battery powered, the average power consumption > of the entire communication part of a sensor is limited to ~ 10mW max.At 3.3V, that's only 3.3mA. That seems hardly enough to keep a receiver running all the time and to transmit occasionally at 10 to 50mA.> > Is there a wireless technology/modules on the market that would allow > such power budget? > > Would it be possible to develop such technology using existing > transceiver ICs or modules? > > (Cost, operating band, compliance, acceptance, etc. are outside of > consideration at this point).Are there any time-division systems where the host sends a broadcast polling command and each sensor transmits at a defined time slot offset from the polling? That means that after the polling command is received, both transmitter and receiver could shut down until time to send, then wake up the receiver until just before the next polling signal. Does the system really respond to the sensors in 100mSec? If not, would it be possible to poll each sensor every 10 seconds and have it return 100 readings? With a lower transmit duty cycle, you might meet the power constraints. The host could then assemble a continuous record with 10 seconds of delay.>Mark Borgerson
Reply by ●January 6, 20112011-01-06
Hi Vladimir, On 1/5/2011 8:09 PM, Vladimir Vassilevsky wrote:> There is a network of ~100 wireless sensors, communicating to a single > host. All sensors are located within ~50..100m from the host in the > typical urban environment. Ideally, it would be desirable to poll each > sensor at least 10 times/sec. When polling the sensors, we have to get > just several bits of the status information from each sensor.Presumably, you want ~100ms latency and not just "10Hz rate" (i.e., you can't pack/compress data in the mote and then deliver it "less often") Do the sensors *have* to talk to that single host? What constraints are there on the actual topography of "mote deployment"? E.g., are they evenly distributed in a "50-100m" radius? Or, are they clumped in (arbitrary) areas? (e.g., could you use a mesh to reduce the range each device has to handle) What if a device fails to answer its poll? Is there some system cost to this? Instead of an "interactive" poll, consider synchronizing (short term) all of the nodes and assigning timeslots to each mote. Instead of polling each *individual* mote, the host can be seen as "polling the network". If you can tolerate *not* getting a response from a mote, then this can be exploited in the mote: "don't power up the transmitter if you don't have anything interesting to say" (since you know how the host will interpret your silence). Couple this with a periodic "are you still there" polling beacon (which "requires" acknowledgement) You can include this coupled with a mechanism to specifically talk to a *particular* mote. This gives you a way of listening to the "field" and still interacting with specific parts of it in more "directed" ways. Can you migrate "parts of the application" into the mote to reduce it's need for communication with the "host"? I.e., what if the mote *doesn't* get a chance to upload its observation(s) to the host... does it just discard them or can it act on them? What is the cost to replace the battery (i.e., can you increase the power budget or are there other factors driving that figure)? I'm using bits of "all of the above" to drive my Pd down (though most of my motes don't *have* to look at data at 10Hz/24/7). Note that some of these issues also improve reliability of the "network" and, thus, "system".> Problem: as sensors are battery powered, the average power consumption > of the entire communication part of a sensor is limited to ~ 10mW max. > > Is there a wireless technology/modules on the market that would allow > such power budget? > > Would it be possible to develop such technology using existing > transceiver ICs or modules? > > (Cost, operating band, compliance, acceptance, etc. are outside of > consideration at this point).
