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Time-Optimal Information Exchange on Multiple Channels. TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box .: A A A A A A A A A A. Time-Optimal Information Exchange on Multiple Channels. n:= # nodes. Problem :.
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Time-Optimal Information Exchange on Multiple Channels TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAAAAA
Time-Optimal Information Exchange on Multiple Channels n:= # nodes Problem:
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Problem: Have information ? Disseminate to all!
Time-Optimal Information Exchange on Multiple Channels Problem: ? Disseminate to all!
Time-Optimal Information Exchange on Multiple Channels Problem: ? Disseminate to all! Easy: O(n) Faster?
Time-Optimal Information Exchange on Multiple Channels n:= # nodes Problem: 1 5 2 3 Unique IDs 1…n 4 n
Time-Optimal Information Exchange on Multiple Channels I can: send / receive reacheachnode
Time-Optimal Information Exchange on Multiple Channels I can: ? send / receive reacheachnode
Time-Optimal Information Exchange on Multiple Channels I can: send / receive reacheachnode nocollisiondetection
Time-Optimal Information Exchange on Multiple Channels I can: send / receive reacheachnode nocollisiondetection 101 Mhz 117 Mhz 132 Mhz … switchchannels synchronus
Time-Optimal Information Exchange on Multiple Channels I can: complexity computation: free radio: time 1 send / receive reacheachnode nocollisiondetection switchchannels synchronus
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information One Information / log n bits per message O(1) => Ω( k )
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Multi channel ? onechannel + log n => Ω( k ) [Kushilevitz, Mansour SIAM JComp 1998]
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information What can I do? TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Communicate in parallel on different channels 1 TREE 3 2 4 5 7 6 8 9 14 10 15 12 11 13 16
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Communicate in parallel on different channels TREE 2 4 8 9
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information TREE O( k + log n)
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information What if k < log n? n channels TREE O( k ) if k > log n
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information What if k < log n?
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Listens on channel 1 Listens on channel 2 Listens on channel 3 Listens on channel 4 Balls into Bins Send on random channel 1…2 k
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Listens on channel 1 Listens on channel 2 Listens on channel 3 Listens on channel 4 Balls into Bins Send on random channel 1…2 k
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Pr no collision Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Pr no collision TREE Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known k ID=1…2 Pr no collision TREE Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Repeat k times k ID=1…2 Pr no collision Balls into Bins
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known What if ? Repeat k times k ID=1…2 Pr [no collision] > 1- If k Balls into Bins 2 channels TREE O( k ) if
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known What if ? Unique Subset Time: O( k )
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Unique Subset
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Unique Subset
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Unique Subset Send on random channel }.
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Unique Subset Send on random channel . Send on random channel }.
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Pr[atmosthalf messages collide] 1- Unique Subset Not too big … Not too small … Just right! Send on random channel . Send on random channel }.
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels ? ? Unique Subset ? Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Unique Subset Channel 1 Channel 3 Send k times
Time-Optimal Information Exchange on Multiple Channels n:= # nodes k:= # information Assume: k known Example: 3 channels Pr[atmosthalf messages collide]1- Unique Subset O( k )