802.11 Packet scheduler for Power Saving



******************Source Structure
==================================
root/                       
   k/                       /* kernel module */
   pcap_data/               /* pcap testing data */
   README
   Makefile
   *.c || *.h               /* application level code */


*******************Compile
==================================
Use "make" to compile source codes. The top level Makefile only compiles application level code. To compile kernel module, use the Makefile in the folder "k".


********************Usage
==================================
Several executables are provided after making the project. They are:
    ./scheduler
    ./replay_pcap
The usage of each executable will be given when input the above commands.

And Kernel object is located at: ./k/k_flow_control.ko


*********************Scenario
==================================
Assume:
    <TARGET_IP> = 192.168.10.1
    <ORIGINAL_TRAFFIC> = pcap_data/brower2.pcap

1. Insert kernel object:
    insmod ./k_flow_control.ko target=<TARGET_IP>

2. Provide sharped traffic information to the kernel module:
    ./scheduler -g -t <TARGET_IP> -s <ORIGINAL_TRAFFIC>

    /var/log/messages should print:
            DD receiverd, flow_control open, where "DD" is the number of
            traffic data the kernel module accepts. Now it is ready to
            track and delay these packets.

3. Replay the original packets
    ./replay_pcap -t <TARGET_IP> -s <ORIGINAL_TRAFFIC>

4. The traffic should be sharped by the kernel module and sent to the machine with <TARGET_IP>. In that machine, you can obtain the traffic again into a pcap file. Assuming the file name is <SHARPED_TRAFFIC>, then, the following command can be used to compare the actual result with the estimated one.
    ./scheduler -c <SHARPED_TRAFFIC> -t <TARGET_IP> -s<ORIGINAL_TRAFFIC>


*****************Comparison output
==================================
The output of the comparsion contains several columns: 
[index] - [packet identifier]:
    index is a self increment number which is used to count the packets.
    packet identifer consists of the combination of IP checksum and TCP/UDP checksum.

[Estimated]:
    The time difference of current packet and previous packet in the estimation. The estimation comes from the traffic scheduler.

[Actual]
    The time difference of current packet and previous packet actually received in the target machine.

[Diff]:
    The time difference of estimated and actual packet arrival time for current packet.

[Flag]:
    Due to the traffic burst, packet loss is unavoidable. If application fail to match a estimated packet in the result, this flag is cleaned. otherwise it is "M" which means "result matched". Meanwhile, if this flag is unset (packet loss), the "Actual" column will be "---" since the data cannot be provided.