WinlabMadwifi -> Driver Wish List = MAC experiments envisioned = The testbed is designed to support an open API for MAC protocol design. While the ultimate goal is to provide maximum flexibility for end-user’s arbitrary MAC algorithm, we have a near-term goal to implement and verify a series of cutting-edge MAC protocols derived from IEEE 802.11 MAC, but has very important variations to improve the performance of wireless ad-hoc networks. Following MAC experiments are going to be verified in Orbit testbed and all of them have some modifications of basic CSMA/CA mechanism. * '''DCMA (Data-driven Cut-through Multiple Access Protocol''' This new MAC protocol uses a new combo ACK/RTS frame to resolve the contentions within the same multi-hop flow. Thus, the RTS and ACK frame formats needs to be changed. Correspondingly, it is necessary to implement a new control frame’s handling routine for 802.11 chip’s firmware or driver. * '''MACA-P protocol''' This protocol uses an innovative way to establish parallel transmissions. Basically, the nodes which exchange an RTS/CTS reservation do not transmit the DATA frame immediately, but waiting for a time gap to let multiple transmissions happen in parallel. Thus, both the format and timing relationship between the control frames and DATA frames needs to be adjusted. * '''D-LSMA protocol''' Distributed Link Scheduling Multiple Access is designed to facilitate real-time multi-hop flows. Using ns-2 simulation, it has been seen to give ~30% throughput improvement for wireless mesh network. The protocol suppresses the ACK frames and extends RTS/CTS format for support periodic traffic patterns. Thus, to realize this protocol, the ACK has to be disabled and the frame format needs to be changed. = Desired Features = The features requested are divided into four groups == Basic MAC level changes == The following features are desirable * '''Can the value of Carrier Sensing threshold of CSMA be changed or disabled? ''' By doing that we could calibrate and adjust the interference range of a node. And this interference range is a very dedicate and key parameter for verify a series of MAC protocols physically. * '''Could the timing relationship of the control frames be adjusted? ''' We know the SIFS, DIFS, EIFS are inter-frame timings used in various version of 802.11 standards. And we think it might be a flexible parameter to be set conveniently. But we need some instruction and documentation to do this. * '''Can we select a Backoff number (of slots) instead of a random-selected number between CWmin and CWmax in addition to change the values of CWmin and CWmax and the time duration of the slot? ''' We mean if a more generalized algorithm can be implemented to replace that random-number generation part or not * '''Can we obtain bit error statistics of CRC function for every received MAC frame (MPDU)? ''' This is used for techniques related to channel estimation. * '''Can the ACK frames for unicast communication be suppressed? ''' In other words,can MAC chip just act like a simple FIFO sender and receiver without invoke any MAC state-machines == Modify existing frames or create new frames == * '''Does the MAC implementation provide the ability to generate new control frames,in addition to the RTS, CTS and ACK?''' * '''Does MAC implementation provide the ability to change format of current control frames?''' == AP mode of operation == Can the STA be used as an AP? i.e is the Master mode available? == Statistics report from driver == In addition to the MAC level support as described above, the following statistics reported by the driver would be useful for cross layer adaptation. These parameters are as follows: ||'''PHY Layer'''|| || Link Quality || ||Signal level || || Noise level || || RSSI || || Signal to noise ratio (dBm)|| || Modulation Scheme (or PHY Rate used)|| || '''MAC layer'''|| || No. of retries per packet || || Number of frames successfully transmitted || || Number of buffer overflows (This will give an indication as to whether the packet loss is at the link or due to buffer overflow)|| || Current Contention Window size || || Current buffer occupancy || || Media access delay Some additional counters that could be useful are * !RxOverrun * !RxMacCrcErr * !RetryLong * !RetryShort * !MaxRetries * !NoAck * !NoCts * !RxAck * !RxCts * !TxAck * !TxMc * !TxBc * !TxUcPackets * !TxBeacon * !RxBeacon * !DupFram * !HostTxBytes * !HostRxBytes * TxRTS * TxCTS