public int getNormalizedSignalStrength() {
		// TODO test and rewrite (taken from placelab)
		// return an int 0-100 depending on the signal strength, or -1 if
		// unsupported
		// linear heuristic based on histogram of logs at IRS
		// -45 => 100, -60 => 67, -75 => 33, -90 => 0
		// int retval = (100*(90 + rssi)) / 45;

		// JWS changed this since supporting particlefilters is easier this way
		// will affect the colouring on XMapDemo - more yellows and less
		// reds/greens
		int retval = rssi + 100;
		if (retval < 0)
			retval = 0;
		if (retval > 100)
			retval = 100;
		return retval;
	}