Dallas . Maximum has an application note #148 that covers discussion of reliable 1 wire networks. You can look at Application Note 148 here.

If you are running the one wire device on direct connected power (I think this is what you implied) then it is very desireable for you to provide some degree of isolation between the long cable and the +5 and GND pins of your 8052 board. I would run the +5 volts through a 270 ohm resistor and into a 4.7 -> 22 uF capacitor at the connection point of the cable. I would put a series resistor on the signal line at the point it comes on the board and then place a zener diode on this signal line. The zener should have its anode to GND and its cathode connected to the 8052 port pin where the series resistor brings the signal in. You can try starting with series resistors of 10 ohm to 33 ohms. The zener diode should be 5.6 volt zener.

Erik suggested a small capacitor across the signal line to ground. This will help but you should check the waveform of the active signal to make sure the capacitance does not interfere with the normal signalling to / from the 1 wire device. Too big of a capacitance will kill the protocol. You would use an oscilloscope to check this.
Hope that helps
Michael Karas