[Tinyos-2-commits] CVS: tinyos-2.x/doc/txt tep123.txt, 1.11, 1.12 tep124.txt, 1.5, 1.6

Thu Nov 20 22:54:42 PST 2008

Update of /cvsroot/tinyos/tinyos-2.x/doc/txt
In directory ddv4jf1.ch3.sourceforge.com:/tmp/cvs-serv13568

Modified Files:
	tep123.txt tep124.txt 
Log Message:
phils comments

Index: tep123.txt
===================================================================
RCS file: /cvsroot/tinyos/tinyos-2.x/doc/txt/tep123.txt,v
retrieving revision 1.11
retrieving revision 1.12
diff -C2 -d -r1.11 -r1.12
*** tep123.txt	21 Nov 2008 01:05:50 -0000	1.11
--- tep123.txt	21 Nov 2008 06:54:40 -0000	1.12
***************
*** 67,77 ****
  successfully received.

! CTP has several mechanisms in order to improve delivery reliability,
! but it does not promise 100\% reliable delivery. It is best effort, but
! a best effort that *tries very hard.*

! CTP is designed for relatively low traffic rates. Bandwidth-limited systems
! might benefit from a different protocol, which can, for example, pack
! multiple small frames into a single data-link packet.

--- 67,81 ----
  successfully received.

! CTP has several mechanisms in order to achieve high delivery
! reliability, but it does not promise 100\% reliable delivery. It is a
! best effort protocol.

! CTP is designed for relatively low traffic rates such that there is
! enough space in the channel to transmit and receive routing frames
! even when the network is forwarding collection data
! frames. Bandwidth-limited systems or high data rate applications might
! benefit from a different protocol, which can, for example, pack
! multiple small frames into a single data-link packet or employ rate
! control mechanisms.

***************
*** 164,168 ****
  asked to forward the same packet twice due to a routing loop, it will
  drop the packet. However, if it suppresses packet instances, then it
! will route succesfully in the presence of transient loops unless the
  THL happens to wrap around to a forwarded packet instance.

--- 168,172 ----
  asked to forward the same packet twice due to a routing loop, it will
  drop the packet. However, if it suppresses packet instances, then it
! will route successfully in the presence of transient loops unless the
  THL happens to wrap around to a forwarded packet instance.

***************
*** 238,247 ****

   1) The routing table is empty (this also sets the P bit)
!  2) The node's routing ETX increases by >= 1 trasmission
   3) The node hears a packet with the P bit set

  The implementation augments the LEEP link estimates with data
  transmissions. This is a direct measure of ETX. Whenever the data path
! transmits a packet, it tells the link estimator the destimation and
  whether it was successfully acknowledged. The estimator produces an
  ETX estimate every 5 such transmissions, where 0 successes has an ETX
--- 242,251 ----

   1) The routing table is empty (this also sets the P bit)
!  2) The node's routing ETX increases by >= 1 transmission
   3) The node hears a packet with the P bit set

  The implementation augments the LEEP link estimates with data
  transmissions. This is a direct measure of ETX. Whenever the data path
! transmits a packet, it tells the link estimator the destination and
  whether it was successfully acknowledged. The estimator produces an
  ETX estimate every 5 such transmissions, where 0 successes has an ETX
***************
*** 257,262 ****
  switch to another candidate neighbor.

! The component ``tos/lib/net/le/LinkEstimatorP`` implements the
! link estimator. It couples LEEP-based and data-based estimates.

  6.2 Routing Engine
--- 261,267 ----
  switch to another candidate neighbor.

! The component ``tos/lib/net/4bitle/LinkEstimatorP`` implements the
! link estimator. It couples LEEP-based and data-based estimates as
! described in [4]_.

  6.2 Routing Engine
***************
*** 275,279 ****

  The component ``tos/lib/net/ctp/CtpForwardingEngineP`` implements the
! forwarding engine. It has five repsonsibilities:

   1) Transmitting packets to the next hop, retransmitting when necessary, and
--- 280,284 ----

  The component ``tos/lib/net/ctp/CtpForwardingEngineP`` implements the
! forwarding engine. It has five responsibilities:

   1) Transmitting packets to the next hop, retransmitting when necessary, and
***************
*** 361,362 ****
--- 366,370 ----
         Conference on Networked Systems Design and Implementation (NSDI), 2004.
  .. [3] TEP 119: Collection.
+ .. [4] Rodrigo Fonseca, Omprakash Gnawali, Kyle Jamieson, and Philip Levis.
+        "Four Bit Wireless Link Estimation." In Proceedings of the Sixth Workshop
+        on Hot Topics in Networks (HotNets VI), November 2007.

Index: tep124.txt
===================================================================
RCS file: /cvsroot/tinyos/tinyos-2.x/doc/txt/tep124.txt,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** tep124.txt	18 Oct 2007 16:11:57 -0000	1.5
--- tep124.txt	21 Nov 2008 06:54:40 -0000	1.6
***************
*** 36,42 ****
  link from a neighbor by estimating the ratio of successfully received
  messages and the total transmitted messages. LEEP appends in-bound
! packet reception rate (PRR) estimates to packets. Other nodes hearing 
  these packets can combine the in-bound PRR values with their own
! in-bound values to compute bi-directional link quality.

  2. Definitions
--- 36,48 ----
  link from a neighbor by estimating the ratio of successfully received
  messages and the total transmitted messages. LEEP appends in-bound
! packet reception rate (PRR) estimates to packets. Other nodes hearing
  these packets can combine the in-bound PRR values with their own
! in-bound values to compute bi-directional link quality. Thus, LEEP is
! a discovery and link table bootstrapping mechanism. The link quality
! is often fine-tuned using different mechanisms.
! 
! Link quality estimates obtained using LEEP are often used as a
! bootstrapping values in the link quality table; data transmission
! statistics are later used to make these estimates more accurate.

  2. Definitions
***************
*** 104,108 ****
  neighbors. The Link Information entry on the LEEP frame allows the
  receiver node to find the out-bound link quality to the transmitter
! node identified by the data link source address.

  3.3 LEEP Frame
--- 110,124 ----
  neighbors. The Link Information entry on the LEEP frame allows the
  receiver node to find the out-bound link quality to the transmitter
! node identified by the data link source address. Thus, LEEP is also a
! way for nodes to discover new nodes and links in the network.
! 
! Link quality estimation is inherently imperfect - data transmission
! and link quality estimation might be done at different timescales. The
! PRR for LEEP frames (broadcast) and data frames (unicast) might be
! different. So LEEP is better used as a link quality bootstrapping
! mechanism. The link quality estimate can be made more accurate later
! using data transmission statistics.
! 
! 

  3.3 LEEP Frame
***************
*** 180,183 ****
--- 196,203 ----
  sent as a LEEP payload, are sent.

+ Another reference implementation resides in
+ ``tinyos-2.x/tos/lib/net/le``. This implementation is described in
+ detail in [2]_.
+ 
  5. Author's Address
  ============================================================================
***************
*** 196,197 ****
--- 216,220 ----

  .. [1] TEP 123: The Collection Tree Protocol.
+ .. [2] Rodrigo Fonseca, Omprakash Gnawali, Kyle Jamieson, and Philip Levis.
+        "Four Bit Wireless Link Estimation." In Proceedings of the Sixth Workshop
+        on Hot Topics in Networks (HotNets VI), November 2007.