1. Direct Stream Request Protocol (DSRP)
Month 2000
doc.: IEEE /xxx
July 2002
Direct Stream Request Protocol (DSRP)
Menzo Wentink
Intersil Corporation
Menzo Wentink, Intersil
Menzo Wentink, Intersil

2. July 2002
DSRP Protocol Outline
DSRP is a signaling mechanism to set up direct streams between two stations in the same BSS
if a direct stream is active, MPDUs may be sent directly, i.e. not via the AP
power save mode shall not be entered while a direct stream is active
The AP has the option to allow or disallow direct streams in the BSS
A timout is used to end direct streams
no active teardowm mechanism
Menzo Wentink, Intersil

3. Involved Parties Sender Receiver AP
July 2002
Involved Parties
Sender
the station that requests the direct stream
Receiver
the station that is the intended recipient of the direct stream AP
the Access Point in the BSS
Menzo Wentink, Intersil

4. Direct Stream State Machine
July 2002
Direct Stream State Machine
1. Idle
fail
2. Activation
4. Encryption
handshake
3. Probing
pass
5. Active
6. Idle_timeout
Menzo Wentink, Intersil

5. 1. Idle The direct stream is idle
July 2002
1. Idle
The direct stream is idle
all traffic for a particular receiver is routed via the AP
the nodes may be in PSM
Menzo Wentink, Intersil

6. 2. Activation Request and response are routed through the AP
July 2002
2. Activation
Sender AP
Receiver
DSRP-request
DSRP-request
DSRP-response
DSRP-response
Request and response are routed through the AP
the request and response contain capability information of sender and receiver respectively
the receiver and the AP can reject the request
if the receiver is not in the BSS, the AP will reject the request
After a succesful activation handshake, the receiver shall not go into powersave for a duration of idle_timout
Menzo Wentink, Intersil

7. DSRP-probe (succesful)
July 2002
3. Probing (optional)
Sender
Receiver X
DSRP-probe (failed) X
DSRP-probe (failed)
DSRP-probe (succesful)
After activation, DSRP probes may be used to establish a transmission rate
DSRP-probes are (acknowledged) management frames which are discarded by the receiver
The sender may also use data frames for probing
Menzo Wentink, Intersil

8. 4. Encryption handshake (optional)
July 2002
4. Encryption handshake (optional)
After the activation, the nodes may engage in an encryption handshake
the encryption handshake for direct streams is optional and outside the scope of e
the handshake may be routed direct or via the AP
Menzo Wentink, Intersil

9. July 2002
5. Active
The direct stream is active after a successful activation procedure
frames may be sent directly to the receiver
Menzo Wentink, Intersil

10. July 2002
6. Idle_timout
The direct stream goes Idle when no successful direct frame exchange was conducted between the sender and the receiver during a period of idle_timout.
the idle_timeout should be in the same order as a regular powersave timout.
Menzo Wentink, Intersil

11. DSRP SME Primitives MLME-DSRP.request MLME-DSRP.indication
July 2002
DSRP SME Primitives
MLME-DSRP.request
MLME-DSRP.indication
MLME-DSRP.response
MLME-DSRP.confirm
Menzo Wentink, Intersil

12. DSRP Action Frames DRSP-request DSRP-response DSRP-probe
July 2002
DSRP Action Frames
DRSP-request
contains capabilities and MAC address of sender
DSRP-response
contains capabilities and MAC address of receiver
possible responses and reason codes are
accepted
rejected by AP (policy or receiver not in BSS)
rejected by receiver (security or power save constraints)
DSRP-probe
contains random data, at any given length. The MPDU shall be discarded by reciver, only the ACK is relevant.
Menzo Wentink, Intersil

13. DSRP Message Flow Diagrams*
July 2002
DSRP Message Flow Diagrams*
* thick arrows denote a complete frame exchange, possibly including ACKs, RTS/CTS, CTS-to-self and/or fragmentation.
Menzo Wentink, Intersil

14. I. Succesful/failed request
July 2002
I. Succesful/failed request
Sender AP
Receiver
SME
MAC
MAC
SME
MAC
SME
MLME-
DSRP.request
DSRP-request
MLME-
DSRP.indication
MLME-
DSRP.response
MLME-
DSRP.indication
DSRP.request
DSRP.response
MLME-
DSRP.response
DSRP-response
MLME-
DSRP.indication
MLME-
DSRP.response X X
MLME-
DSRP.confirm
DSRP.probes
(optional)
Menzo Wentink, Intersil

15. II. Request denied by AP Sender AP Receiver SME MAC MAC SME MAC SME
July 2002
II. Request denied by AP
Sender AP
Receiver
SME
MAC
MAC
SME
MAC
SME
MLME-
DSRP.request
DSRP-request
MLME-
DSRP.indication
DSRP-response
MLME-
DSRP.confirm
MLME-
DSRP.response
Menzo Wentink, Intersil

16. direct frame exchanges
July 2002
III. Idle timeout
Sender
Receiver
SME
MAC
MAC
SME
direct frame exchanges
MLME-
DSRP.indication
MLME-
DSRP.indication
idle_timeout
idle_timeout
Menzo Wentink, Intersil