Index of /data/wichmo/outdoor

[ICO]NameLast modifiedSizeDescription
[PARENTDIR]Parent Directory  -  
[DIR]navacchio-poligono2/2009-03-18 17:18 -  
[DIR]5-navpol/2009-03-18 17:18 -  
[DIR]marinella/2008-05-06 15:11 -  
[DIR]2-marine/2008-05-06 15:11 -  
[DIR]navacchio-poligono1/2008-05-06 15:11 -  
[DIR]3-navpol/2008-05-06 15:11 -  
[DIR]navacchio-zingari/2008-02-15 11:01 -  
[DIR]4-navzin/2008-02-15 11:01 -  
[DIR]marinella1-norm/2008-02-15 11:01 -  
[DIR]1-marine/2008-02-15 11:01 -  
[DIR]navacchio-poligono/2007-12-20 12:35 -  
[DIR]6-navpol/2007-12-20 12:35 -  
Data in the directories 1-marine, 2-marine, 3-navpol, 4-navzin,
5-navpol, 6-navpol are measured in Navacchio (Pisa) in April, 2006 using
two laptops in 802.11 ad hoc mode at different distance on a wide
uncultivated field.  The laptops are two IBM Thinkpad R40e laptops
(Celeron 2 GHz with 256 MB ram running Debian Linux with a 2.6.8
kernel), equipped with CNet CNWLC-811 wireless cards and standard
drivers.

Retransmission, RTS/CTS and fragmentation are all disabled, long
preambles are used.  Frames are sent to the network card with a
intertransmission time varying from 5 to 20 ms for 11, 5.5, 2 and 1 Mb/s
speeds (be sure to check the transmission times).  The beacon is sent
every 102.4ms.

Each file name is built like this: rcv_SPEED_DISTANCE_LENGTH

where SPEED is the transmission speed (1, 2, 5.5, 11 Mb/s),
DISTANCE is the distance between the transmitter and the receiver
and LENGTH is the frame length (500, 1000, 1500 bytes).

The fields marked with an asterisk (*) below are always 0, because the
network card used for the measurements in this directory cannot give
these statistics.

FORMAT OF THE DATA

Each line contains these fields:
 - receive time, or 0 when packet is not received at all
 - lenght of the frame in bytes to data: to obtain the whole frame
   lenght one must add an LLC/SNAP header, CRC and MAC header. There are
   three data lengths: 500, 1000 and 1500 bytes.  The respective frame
   durations can be computed as:
		+-------+-------+-------+-------+-------+
		|len[ms]| 1 Mb/s| 2 Mb/s|5.5Mb/s|11 Mb/s|
		+-------+-------+-------+-------+-------+
		| 500 B | 5.154 | 2.954 | 1.555 | 1.154 |
		+-------+-------+-------+-------+-------+
		|1000 B | 9.154 | 4.954 | 2.282 | 1.518 |
		+-------+-------+-------+-------+-------+
		|1500 B |13.154 | 6.954 | 3.009 | 1.881 |
		+-------+-------+-------+-------+-------+
 - sequence number starting from 0
*- quality level read from the network card
 - signal level read from the network card: multiply by 0.6 to get dB
*- noise level read from the network card
 - status: 1 for lost frames, 0 for received frames
*- number of corrupted bits in frames received with wrong CRC