Identify the Vendor from MAC Address for wifi devices

http://www.coffer.com/mac_find/?string=intel

MadWifi: linux driver for wireless ethernet card

MadWifi 'First Time User' HOWTO

http://madwifi-project.org/wiki/UserDocs/FirstTimeHowTo

How to build the ad-hoc network:

https://help.ubuntu.com/community/WifiDocs/Adhoc
https://help.ubuntu.com/community/WifiDocs/Driver/Madwifi

Specifically, for Atheros card, the restricted Madwifi driver supports adhoc mode through the creation of a new VAP.


1. remove the ath_pci module with modprobe
$ sudo modprobe -r ath_pci

2. Now re-insert the module with the option of creating it in ad-hoc mode:
$ sudo modprobe ath_pci autocreate=adhoc

3. then, build a ad-hoc network by assigning the different IP addresses for different host computer:
$ sudo iwconfig eth0 essid 'NAMEofAdhoc'
for example, for the first computer,
$ sudo ifconfig eth0 169.254.114.102 netmask 255.255.0.0
for the second computer,
$ sudo ifconfig eth0 169.254.114.103 netmask 255.255.0.0

Using the following command to change the frequency:
$ sudo iwconfig eth0 freq 2.462G

Iperf: a tool to measure the bandwidth and the quality of a network

How to install and use iperf
http://openmaniak.com/iperf.php

The source code is available at:
http://sourceforge.net/projects/iperf/

iperf(1)

NAME

iperf - Modified version of a tool for measuring maximum TCP and UDP bandwidth in the sense that also a bandwidth for TCP may be specified

DESCRIPTION

This program iperf is the modified version of the original iperf program. This version allows that also a bandwidth for TCP may be specified. This can be done with the option -a which was not available in the original version.

USAGE

Usage: iperf [-s|-c host] [-p port] [-t secs] [-w bytes] ...
      iperf [-h|--help] [-v|--version]

Client/Server:
 -f, --format    [kmKM]   format to report: Kbits, Mbits, KBytes, MBytes
 -i, --interval  #        seconds between periodic bandwidth reports
 -l, --len       #[KM]    length of buffer to read or write (default 8 KB)
 -m, --print_mss          print TCP maximum segment size (MTU - TCP/IP header)
 -p, --port      #        server port to listen on/connect to
 -u, --udp                use UDP rather than TCP
 -w, --window    #[KM]    TCP window size (socket buffer size)
 -B, --bind         bind to , an interface or multicast address
 -M, --mss       #        set TCP maximum segment size (MTU - 40 bytes)
 -N, --nodelay            set TCP no delay, disabling Nagle's Algorithm
 -V, --IPv6Version        Set the domain to IPv6

Server specific:
 -s, --server             run in server mode
 -D, --daemon     run the server as a daemon

Client specific:
 -a, --tcp_bandwidth \    for TCP, bandwidth to send at in bits/sec
    #[KM]    (default no bandwidth limit used)
 -b, --bandwidth #[KM]    for UDP, bandwidth to send at in bits/sec
                          (default 1 Mbit/sec, implies -u)
 -c, --client       run in client mode, connecting to
 -n, --num       #[KM]    number of bytes to transmit (instead of -t)
 -t, --time      #        time in seconds to transmit for (default 10 secs)
 -F, --fileinput    input the data to be transmitted from a file
 -I, --stdin              input the data to be transmitted from stdin
 -P, --parallel  #        number of parallel client threads to run
 -S, --tos       #        set type-of-service for outgoing packets
 -T, --ttl       #        time-to-live, for multicast (default 1)
 -W, --windowSizeSuggest  Run the client so as to suggest a suitable window size (default off)

Miscellaneous:
 -h, --help               print this message and quit
 -v, --version            print version information and quit

[KM] Indicates options that support a K or M suffix for kilo- or mega-

The TCP window size option can be set by the environment variable
TCP_WINDOW_SIZE. Most other options can be set by an environment variable
IPERF_, such as IPERF_BANDWIDTH.

Report bugs to 

ORIGINAL IPERF DOCUMENTATION

http://dast.nlanr.net/Projects/Iperf/

The documentation.

http://dast.nlanr.net/Projects/Iperf/iperfdocs_1.6.html

The Iperf V. 1.6 User Docs.

SEE ALSO

jperf(1)

---

http://staff.science.uva.nl/~jblom/gigaport/tools/man/iperf.html

Google Code University

http://code.google.com/edu/

Python

• Understanding Python
• Python Design Patterns, Part 1
• Python Design Patterns, Part 2
• Python 3000
• Python Object Model
• Python Internals

Install Debian Linux in Gateway laptop zz

http://www.winlab.rutgers.edu/~xjing/prj/InstallDebianLinux.htm

More about adding a user in linux

Some distro configures useradd / adduser commands to create a directory while adding a user account. I suggest you use -m switch to create home directory for new user.

Code:

useradd -m -s /bin/bash userName
passwd userName

To solve your current problem, login as root and create directory manually:

Code:

cd /home
ls -l
mkdir scheiber
chmod  0700 scheiber
chown -R scheiber:scheiber scheiber

To check the permission:
http://www.howtogeek.com/howto/ubuntu/add-a-user-on-ubuntu-server/

python tutorial

http://docs.python.org/tutorial/controlflow.html#SECTION006720000000000000000
http://bytes.com/topic/python/

Merry Christmas & Happy New Year

New year comes as expected.
All the happiness and love with you!

Set Failed on device wlan

For some wireless adapters, we can set the monitor mode, in order to capture all the headers information and transmission by others over the air.

According to wireshark wiki, the following command is used in linux:
sudo iwconfig wlan1 mode monitor

But I kept receive the error message "set Failed on device wlan1".

Finally, I found that I need turn the device off first by
sudo ifconfig wlan1 down
sudo iwconfig wlan1 mode monitor
sudo ifconfig wlan1 up.

Then it rocks as you want now :)

HowTo:Checkout SVN in Windows ZZ

http://vegastrike.sourceforge.net/wiki/HowTo:Checkout_SVN
http://vegastrike.sourceforge.net/wiki/HowTo:Checkout_SVN#Tortoise_SVN

mbr被破坏无法进入ubuntu 9.10 ZZ

进入LiveCD 打开终端：

sudo fdisk -l查看磁盘信息。   找到 / ,/boot的对应分区。
我这里是/dev/sda11 在/     ,    /dev/sda3在/boot.

接着我们来挂载：
 sudo mount /dev/sda11 /mnt
 sudo mount /dev/sda3 /mnt/boot  (如果没有对/boot单独分区的话请别打这条了)
 sudo grub-install --root-directory=/mnt /dev/sda

最后重启进入ubuntu打开终端输入 update-grub2

Configuring Ubuntu Linux Remote Access using SSH ZZ

http://www.techotopia.com/index.php/Configuring_Ubuntu_Linux_Remote_Access_using_SSH

http://principialabs.com/beginning-ssh-on-ubuntu/

bbn code

Ported from gr.hier_block to use gr.hier_block2 and from flow_graph to top_block

http://www.mail-archive.com/discuss-gnuradio@gnu.org/msg15066.html
http://1010.co.uk/org/notes.html
http://old.nabble.com/BBN%27s-802.11b-code-td18136664.html

The quick solution is: change io_signature (1,2,...) --> in_signature(1,1,...)
and recompile. :)


-----------------------------------------
Install BBN code for USRP2 @ Ubuntu 9.04 + XCVR2450

svn co https://www.cgran.org/cgran/projects/bbn_80211/branches/usrp2_version bbn_80211

cd bbn_80211/
./bootstrap && ./configure && make
sudo make install

If there are errors when doing "make" on bbn, like:
bbn_tap.cc:: ‘printf’ was not declared in this scope
bbn_tap.cc: ‘fprintf’ was not declared in this scope
....
It is probably the problem of GCC version.

The solution is to add the following declaration on top of each cc files.
#include
#include


#include








Install gnuradio 3.2.2 in Ubuntu 10.04

http://rainflyking.blogspot.com/2010/11/install-bbn-and-gr322-in-ubuntu1004.html

Dell E6410 install Ubuntu 10.04

http://blog.csdn.net/wdove/archive/2010/10/26/5968013.aspx
http://www.downloadatoz.com/driver/articles/fix-dell-latitude-e6410-black-screen-during-ubuntu-10-04-installation.html

Export figure to pdf in Matlab ZZ

In LaTex, if the figure is in pdf format, you can click pdfLaTex just once to generate the output. Otherwise, if the figure is in eps format, you have to click button three times to do the same thing by using the LaTex -> dvi2ps -> ps2pdf workflow.

http://jinghaoxu.blogspot.com/2007/04/export-figure-to-pdf-in-matlab.html

The good thing is, Matlab can export figure to pdf format. Unfortunately, when saving a figure to a pdf file in Matlab, you'll find the figure doesn't fit the layout very well, i.e. there is a large margin from the figure to the page boundary. Those margins will be inserted into the LaTex output when you include these pdf figures.

A solution is:
1) After you plot the figure in Matlab, go to 'File->Export Setup', input the size of the output you want, e.g. Width: 6 inches, Height: 5 inches. Then click 'Apply to Figure' button.
2) Don't close the 'Export Setup' window. Go to 'File->Print Preview->Paper', input the same size in the Width and Height options.
3) Don't close the 'Print Preview' window. Go back to the 'Export Setup' window, and click 'Export', then select pdf format and save it.
4) Check the output pdf file, you'll see it is perfect.

latex 单行或多行公式的排版ZZ

from : http://www.boyeut.com/2007/05/equation.html

1.自动编号的单行公式环境是
\begin{equation}
…
\end{equation}

不参与自动编号的单行公式环境：
\[
…
\]

人工编号的单行公式可以使用Tex原有的行间公式标记
$$公式 \eqno 编号 $$ 将编号放在右边
$$公式 \leqno 编号 $$ 将编号放在左边

引用时候可以直接用$编号$即可。

例如，$$a^2+b^2=c^2 \eqno (**)$$
由公式($**$)即可得到结论。

一般情况下，行间公式 $$…$$也可以用\[…\]表示
但对于这种人工编号的公式，不能用\[..\]代替$$…$$.

2.单个公式很长，需要换行，但仅允许生成一个编号时，可以用split命令

\begin{equation}
\begin{split}
a &= b \\
c &= d
\end{split}
\end{equation}

注意：每行只允许出现一个“&”，使用split命令后，编号上下居中显示。

3.多行公式：

\begin{eqnarray}
左 & 中 & 右\\
左 & 中 & 右\\
…
\end{eqnarray}
该环境对多行公式每行都加自动编号，如果相对某行不加编号，可在换行之前添加命令\nonumber

如果要改变公式的自动编号，可以重设计数器初始值：
\setcounter{equation}{数}
下一个编号自动加1。

4.方程组的排版：
多个公式，每个公式自动编号。

1) gather环境
是下面align环境的一种特殊情形。
\begin{gather}
a &= b \\
c &= d \\
…
\end{gather}
>>1.如果其中某几行使用同一个编号，则需要内嵌一个split环境。
>>2.命令\notag可使当前行不编号。
2) align环境
可使几组公式并排在一起，即在同一行显示多个公式，方法是跟以前一样，使用”&”对齐。
可替代gather环境。
3) 以上几种方程组环境，无论每个公式多小，都会占满一行。使用相应的\gathered，\aligned环境，则只占据公式的实际宽度，整体作为一个特大的符号与其他符号一同处理。
这个结构还可以添加位置参数，以决定与其他符号的竖直对齐方式(b,t)。而且这种环境不再具有自动编号功能。

例如：
\begin{equation}
\left.
\begin{aligned}[b]
a &= b+c \\
d &= b+c
\end{aligned}
\right\}
\Longrightarrow
\qquad a=d
\end{equation}

这里更正参考文献中P149页的一个小错误。就是\right}应该改为\right\}.

【参考文献】
1.陈志杰等，LATEX入门与提高（第二版），高等教育出版社，2006.5

python tutorial video

http://showmedo.com/videotutorials/python