Atmel AVR2070 사용자 설명서

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AVR2070
 
 
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8240B-AVR-06/09 
C sends association response. 
Table A-5-7. Associaton response (direct) 
C  FCF – assoc rsp 
0x8C63 
Seq 
03 
PID 
0x1234 
E1 MAC 
0x3333444455556666 
Coord SA 
0x0000 
MAC Cmd 
02 
R1 SA 
0x0003 
 
R1 stores two addresses: Parent (coord) SA and R1 SA. 
A.5.3 Example 3 – Router R3 connects to Coordinator C 
This example is identical to example 2, except that R3 receives a beacon from R1 as 
well as C.  Since the coordinator C node is accessible directly to R3, it ignores R1, 
because the number of hops are higher than directly connecting to the coordinator C. 
A.5.4 Example 4 – Router R2 connects to Network 
This example shows a multi-hop node being configured.  At the start, assume that 
routers R1 and R3 are already associated to the network. 
R2 powers up, and scans for routers.  It gets a beacon from C, R1, and R3.  Since C 
is far away, its LQI is less than R1's LQI, so R2 ignores C and tries to connect to R1, 
since its signal is stronger than R3's signal. 
R2 sends an association request to R1. This is an “direct association request” 
because the source address is long.  All new nodes send a direct request, since they 
do not yet have a short address. 
Table A-5-8. Association request (direct) 
R2  FCF –assoc req 
0xC863 
Seq 
01 
PID 
0x1234 
R1 SA 
0x0003 
R1 MAC addr 
0x5555444433332222 
MAC 
01 
Parent SA 
0x0003 
Type 
0x02 
 
R1 forwards the association request to C, after re-arranging the packet into an 
“indirect association request”, which has both addresses as short. 
Table A-5-9. Association request (indirect) 
R1 FCF 
–assoc 
req 0x8863 
Seq 
02 
PID 
0x1234 
C SA 
0x0000 
R1 SA 
0x0003 
MAC
CMD
01 
Par SA
0x0003
R2 MAC addr 
0x5555444433332222 
Type
0x02
 
C stores R2's MAC address and assigns a short address to R2.  It then sends back 
an association response frame. 
This is an “indirect association response” frame, since the response is sent through a 
router and not directly to the end node.  Indirect frames use short addresses for both 
source and destination. 
Table A-5-10. Association response (indirect) 
C  FCF – assoc rsp 
0x8863 
Seq 
03 
PID 
0x1234 
R1 SA 
0x0003
C SA 
0x0000
MAC 
02 
Parent SA 
0x0003 
R2 MAC ad 
0x55554... 
R2 SA 
0x0006 
 
R1 receives the frame from C, and notices that the Parent SA matches its own SA.  
This causes R1 to re-package the frame into a “direct association response” frame, 
and to store R2's SA in its child table before sending the association response on to 
R2.