This directory contains "TKN15.4", a platform-independent IEEE 802.15.4-2006
-MAC implementation. The code is in alpha state, under active development, but
-most of the functionality described in the standard is implemented (and
-cursorily tested). The MAC itself is platform-independent, but it requires
-(1) a suitable radio driver, (2) Alarms/Timers with symbol precision and (3)
-some "platform glue" code (defining guard times, etc.). Currently the only
-supported platform is TelosB (however: without additional hardware support on
-TelosB the timing in beacon-enabled mode is not standard compliant).
+MAC implementation. The code is under active development, but most of the
+functionality described in the standard is implemented and tested. The MAC
+itself is platform-independent, but it requires (1) a suitable radio driver,
+(2) Alarms/Timers with symbol precision and (3) some "platform glue" code
+(defining guard times, etc.). Currently the only supported platforms are TelosB
+and micaZ (note: because they do not have a clock that satisfies the
+precision/accuracy requirements of the IEEE 802.15.4 standard -- 62.500 Hz,
++-40 ppm in the 2.4 GHz band -- the timing in beacon-enabled mode is not
+standard compliant).
-Status 6/16/08
---------------
+Status (last updated 5/28/09)
+-----------------------------
Missing functionality:
-- security (not planned)
-- GTS (not planned)
-- PAN ID conflict resolution
-- multiple indirect transmissions to the same destination
+- GTS
+- security services
+- PAN ID conflict notification/resolution
+- indirect transmissions are incomplete, this is missing:
+ -- returning an empty DATA frame when there is no data for the device
+ -- set pending flag if there are multiple indirect transmissions pending
+ -- purging indirect transmissions on MLME_PURGE.request
+ -- keep frame in transaction queue in case CSMA-CA algorithm fails
-Documentation
--------------
-
-A technical report on TKN15.4 is under way and will be available at:
-http://www.tkn.tu-berlin.de/publications/reports.jsp
+Known Issues:
+- resetting the MAC during operation (via MLME_RESET) has not been tested
+- if initial beacon Tx timestamp is invalid, the coordinator will hang
+- frame pending flags are (need to be) always set in the ACK headers
+- transmitting coordinator realignment frames has not been tested
+- using an incoming and outgoing superframe at the same time has not been tested
+- during an ongoing CSMA-CA transmission incoming frames are ignored
+- on a beacon-enabled PAN: if the device cannot find the beacon the DATA frame
+ is not transmitted (but it should be transmitted using unslotted CSMA-CA, see
+ Sect. 7.5.6.1 "Transmission")
Implementation
--------------
MAC interfaces: tinyos-2.x/tos/lib/mac/tkn154/interfaces
CC2420 driver: tinyos-2.x/tos/chips/cc2420_tkn154
TelosB "platform glue" code: tinyos-2.x/tos/platforms/telosb/mac/tkn154
+micaZ "platform glue" code: tinyos-2.x/tos/platforms/micaz/mac/tkn154
Example applications: tinyos-2.x/apps/tests/tkn154
Note: TEP3 recommends that interface names "should be mixed case, starting
interfaces provided by the MAC to the next higher layer deviate from this
convention (they are all caps, e.g. MLME_START).
+Documentation
+-------------
+
+A technical report on TKN15.4 is available here:
+http://www.tkn.tu-berlin.de/publications/papers/TKN154.pdf
+
+TKN15.4 is the basis for the implementation of the TinyOS 15.4 WG:
+http://tinyos.stanford.edu:8000/15.4_WG
+
Copyright
---------
projects / tinyos-2.x.git / blobdiff