Subject: [6lowpan] #121: IESG comment #30 (by the Routing Area Directorate) - Single-criterion Vs. Multi-criteria routing

From: "6lowpan issue tracker" <[email-masked]>
Date: Mon, 26 Jul 2010 17:32:39 -0000

#121: IESG comment #30 (by the Routing Area Directorate) - Single-criterion Vs.
Multi-criteria routing
------------------------------------+---------------------------------------
 Reporter:  carlesgo@…              |       Owner:     
     Type:  enhancement             |      Status:  new
 Priority:  minor                   |   Milestone:     
Component:  routing-requirements    |     Version:     
 Severity:  -                       |    Keywords:     
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 - This section defines

 . three link evaluation metrics: transmission rate and latency (see R05),
 power Tx/Rx (see R02), in addition to link quality associated to physical
 impairments, losses, etc. (see R04, and R06)

 . two node evaluation metrics: power consumption and transmission range
 (which affects connectivity)

 Are these metrics expected to be translated into "routing metrics"?
 Algorithms for multi-criteria routing experience either excessive
 computational complexities or low performance (routing with more than one
 criteria is an NP complete problem). Knowing the limited CPU and memory
 per node it is not clear what are the "acceptable" trade-offs to comply
 with R01 and R10.

 Further their composition as network wide evaluation metrics: path
 delivery ratio, path quality, path reconfiguration (dependent on the
 number of hops) - see R09 results in combinatorial explosion in meshed
 /multi-hop networks. Here also tradeoff between computational complexity
 (time and resources) and memory size, shall be better balanced against
 these "network wide metric" requirements.

-- 
Ticket URL: <http://trac.tools.ietf.org/wg/6lowpan/trac/ticket/121>
6lowpan <http://tools.ietf.org/6lowpan/>

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From: "6lowpan issue tracker" <[email-masked]>
Date: Mon, 26 Jul 2010 17:33:32 -0000

#121: IESG comment #30 (by the Routing Area Directorate) - Single-criterion Vs.
Multi-criteria routing
------------------------------------+---------------------------------------
 Reporter:  carlesgo@…              |        Owner:        
     Type:  enhancement             |       Status:  closed
 Priority:  minor                   |    Milestone:        
Component:  routing-requirements    |      Version:        
 Severity:  -                       |   Resolution:  fixed 
 Keywords:                          |  
------------------------------------+---------------------------------------
Changes (by carlesgo@…):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 Sure, multi-criteria routing is computationally too expensive. The main
 idea is that various single-criteria metrics are available and can be
 chosen to suit the environment or application.

 We added explicit text about this explanation at the end of Section 4.

-- 
Ticket URL: <http://trac.tools.ietf.org/wg/6lowpan/trac/ticket/121#comment:1>
6lowpan <http://tools.ietf.org/6lowpan/>