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In Thread Stack Fundamentals, the four types of devices in a Thread network are outlined on page 5/6:

  • Border Routers
  • Routers
  • Router-eligible End Devices (REEDs)
  • Sleepy End Devices

It is implied by the document that Routers must be able to constantly supply themselves with electricity (hence REEDs must also be able to run constantly if they are upgraded to Routers). However, can REEDs save power and sleep if they aren't currently being used as routers, or must they always be on in case they are needed?

Take, for example, a smart TV supporting Thread, currently acting as a REED. Since no other devices depend on it while it is a REED, can it suspend its network connection and act as a Sleepy End Device, or does the networking component need to be on all the time?

Aurora0001
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  • since the network devices themselves are responsible for connection and disconnection of dependent devices, they are supposed to be alive and awake! – Prashanth Benny Dec 30 '16 at 10:09
  • i am not sure about the sleepy end devices... do they receive signals when they are sleepy? – Prashanth Benny Dec 30 '16 at 10:09
  • @PrashanthBenny the router-eligible end devices don't have any dependent devices I don't think (otherwise they'd be normal routers). Sleepy end devices periodically check for signals but when sleeping, they don't (because the wireless radio is disabled). – Aurora0001 Dec 30 '16 at 10:17
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    if the network doesnt demand it at all to act as a router, it would be fine for it to sleep and take some rest... :D – Prashanth Benny Dec 30 '16 at 10:23
  • does the signalling system (leader or a router) wait for it to wake up(in case if its a TV)? – Prashanth Benny Dec 30 '16 at 10:25
  • according to the definition of a sleepy end device, which states "Sleepy end devices are host devices. They communicate only through their Parent Router and cannot forward messages for other devices" i don't think it is sleeping! he's listening silently....! probably that answers the question here. – Prashanth Benny Dec 30 '16 at 10:29
  • From my understanding, the TV (acting as a REED) would be connected to a parent router which would send messages to it (just like a sleepy end device does). Feel free to post an answer, especially if you have sources from the specification. – Aurora0001 Dec 30 '16 at 10:38
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    here is the site which i had a reference for definitions from. i don't know legit the info is. – Prashanth Benny Dec 30 '16 at 10:48
  • @PrashanthBenny thanks, looks very useful. It seems to sound pretty reliable from what I know about Thread already - I suppose I can always just check what that source says and compare it to the Thread standard to check it's reliable. – Aurora0001 Dec 30 '16 at 11:25
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    according to m conclusion the network component cannot be turned off. unless there is some other way of interrupting the REED's sleep(like a UART interrupt)! – Prashanth Benny Dec 30 '16 at 11:35
  • Sounds like that's the answer then - do feel free to post it and I'll accept that, since it was what I expected really. – Aurora0001 Dec 30 '16 at 11:37
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    Thank you... I just posted an answer! You may edit the answer since I am quite unsure about the logic behind! – Prashanth Benny Dec 30 '16 at 12:16
  • Sleepy devices are usually battery operated and do not forward any data to other thread devices. It wakes every 5 seconds or less to check for parent routers. If the sleepy device detects a signal that requires a connection to the router, it'll wake up immediately. Examples are motion and door sensors. If a router sends a signal to the sleepy device (like blinds) to open or close, it'll take up to 5 seconds to respond. – netrox Aug 08 '22 at 01:51

1 Answers1

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Can it suspend its network connection and act as a Sleepy End Device, or does the networking component need to be on all the time?

They can be sleepy end devices! but, the Network device is still ON.

According to the definition "Sleepy end devices are host devices. They communicate only through their Parent Router and cannot forward messages for other devices" i.e, their network device is not off!

Sleepy end devices will be communicating with their parent router.

Bence Kaulics
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Prashanth Benny
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