Wireless Experiments

Wireless Experiments

I was playing with the wireless routers on Saturday. By that statement, I meant…

(1) flashing new firmware
(2) verifying the left and right antenna for use in antenna select
(3) experimenting with varying transmit power with different types of antenna

As such, i thought it best to document it. Forgive me if i had to do it here. I forget easily.

Flashing a New Firmware

For the WRT54G, i flashed DD-WRT v23 and OpenWRT. I easily fell in love with DD-WRT’s web interface and the number of added features that come with it, that i don’t even know where to use it (given the current setup). I’m not surprised it’s a fave among firmwares.

ddwrt2openwrt

OpenWRT is not much of a hooker, but it provides better command line functionalities. Likewise, i still enjoyed its gui. The tabs look minimalist as it contain only basic functionalities. It doesn’t try to fit in everything in one, thus, is good enough for normal usage. There is also a choice of three install types: micro (no gui), bin (web+ppoe), and pptp (web+pptp). You also have a choice of using .bin or .trx firmware files. One thing i learned from its wiki page, use bin if upgrading from default Linksys firmwares. If from an older openwrt version, it is best to use trx.

There are still other firmwares available: hyperWRT, or its continued development HyperWRT Thibor or HyperWRT+Tofu (never tried and never knew the differences), as well as different flavors of Sveasoft – Alchemy, Talisman, Freeman – with downloadables here.

Antenna Select

Which is left and which is right? I took time to discover myself as forum posts give unreliable (i.e. contradicting) answers. Using netstumber, i came up with the ff. graph as i changed the antenna select from left to right (looking from the front).

antenna_select

Varying Transmit Power

HyperWAP boosts the transmit power to of 84mW maximum. DD-WRT simply provide 251mW max. With the TX power set to max, i checked which will give me better results. Interestingly though, and quite disappointingly, i got the same signal-to-noise ratio a.k.a. SNR. (I need to review my EE notes to explain this.) However, increasing the transmit power from the default value to its maximum gives the ff:

max_power

  • rom

    Watch out – you might fry the router if you boost the xmit power to its maximum. I find that doubling the default (28) is enough to cover a wide area.

    Enable SNMP on all WRT54G DD-WRT routers and then configure MRTG to check it out – that way, you can monitor the entire DilNet WiFi network from your terminal. Got this working on my home router. 😀

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