Subject: [6lowpan] #56: Update Characteristics

From: "6lowpan issue tracker" <[email-masked]>
Date: Wed, 30 Sep 2009 05:20:55 -0000

#56: Update Characteristics
-------------------------------------+--------------------------------------
 Reporter:  [email-masked]  |       Owner:     
     Type:  defect                   |      Status:  new
 Priority:  major                    |   Milestone:     
Component:  usecases                 |     Version:     
 Severity:  -                        |    Keywords:     
-------------------------------------+--------------------------------------
 The list of typical characteristics of LoWPAN nodes must be updated.

-- 
Ticket URL: <http://trac.tools.ietf.org/wg/6lowpan/trac/ticket/56>
6lowpan <http://tools.ietf.org/6lowpan/>

---

From: Dominik Kaspar <[email-masked]>
Date: Wed, 30 Sep 2009 14:05:30 +0800

Hi,

I have addressed the first major comment to the Use Cases draft given
by several reviewers, which was about the typical characteristics of
LoWPANs being out of date. Here is a new list, I hope it better
reflects the current state of the art.

   o  Limited processing capability: the smallest common LoWPAN nodes
      have 8-bit processors with clock rates around 10 MHz.  However,
      the most commonly used models have either 16-bit or 32-bit cores
      (typically ARM7), running at frequencies in the order of tens of
      MHz.

   o  Small memory capacity: common RAM sizes for LoWPAN devices consist
      of a few kilobytes, usually 4K or 8K bytes, but reaching up to
      256K bytes for high-performance models.

   o  Low power: wireless radios for LoWPANs are normally battery-
      operated.  Their RF transceivers often have a current draw of
      about 10 to 30 mA, depending on the transmission power level.  In
      order to reach common indoor ranges of up to 30m and outdoor
      ranges of 100m, the used transmission power is set around 0 to 3
      dBm.  Depending on the processor type, there is an additional
      battery current consumption of the CPU itself, commonly in the
      order of tens of milliamperes.  However, the CPU power consumption
      can often be reduced by a thousandfold by switching to sleep mode.

   o  Short range: the Personal Operating Space (POS) defined by IEEE
      802.15.4 implies a range of 10 meters.  For real implementations,
      the range of LoWPAN radios is typically measured in tens of
      meters, but can reach over 100 meters in line-of-sight situations.

   o  Low bit rate: the IEEE 802.15.4 standard defines a maximum over-
      the-air rate of 250 kb/s, which is most commonly used in current
      deployments.  Alternatively, three lower data rates of 20 kb/s, 40
      kb/s and 100 kb/s are defined.

Greetings,
Dominik

---

From: Dominik Kaspar <[email-masked]>
Date: Wed, 30 Sep 2009 15:45:32 +0800

Hi,

Some small corrections to the list of typical LoWPAN characteristics:

o  Limited processing capability: the smallest common LoWPAN nodes
      have 8-bit processors with clock rates around 10 MHz.  Other
      models exist with 16-bit and 32-bit cores (typically ARM7),
      running at frequencies in the order of tens of MHz.

   o  Small memory capacity: common RAM sizes for LoWPAN devices consist
      of a few kilobytes, usually 4K or 8K bytes.  However, a wide
      variety of RAM sizes is available, reaching from 1K up to 256K
      bytes.

   o  Low power: wireless radios for LoWPANs are normally battery-
      operated.  Their RF transceivers often have a current draw of
      about 10 to 30 mA, depending on the used transmission power level.
      In order to reach common indoor ranges of up to 30 meters and
      outdoor ranges of 100 meters, the used transmission power is set
      around 0 to 3 dBm.  Depending on the processor type, there is an
      additional battery current consumption of the CPU itself, commonly
      in the order of tens of milliamperes.  However, the CPU power
      consumption can often be reduced by a thousandfold when switching
      to sleep mode.

   o  Low bit rate: the IEEE 802.15.4 standard defines a maximum over-
      the-air rate of 250K bit/s, which is most commonly used in current
      deployments.  Alternatively, three lower data rates of 20K, 40K
      and 100K bit/s are defined.

Dominik

On Wed, Sep 30, 2009 at 2:05 PM, Dominik Kaspar <[email-masked]> wrote:
> [...]