3watt cell vs. 6/10watt cell phone????

[Jack]

How much further can you go from a cell tower with a 3 watt cell phone then a handheld 6/10 of a watt portable.
The reason that I ask this is because nextel offered a 3 watt digital cell phone I think its the b370. vs something like there portable i90.

Thanks

Jack

[KevinJames]

Hi Jack

Either the author of TelecomWriting (http://www.telecomwriting.com/reception/index.html) or the link he references on that link (http://www.criterioncellular.com/) may be able to answer the question if no one else does. I personally don't know.

Kev

Jack,

Simple physics says that power decreases as the SQUARE of distance. This means that it takes 4 times the power to double the distance -- so going from .6 watts to 3 watts (5 times the power output) would slightly more than double (square root of 5 is about 2.24..) the range. Determining the actual power that the two phones in question put out would require laboratory test equipment. A nominal 3-watt phone could easily put out only 2 watts if the electronics were inadequate or badly made or matched.

This would be almost true if you had an unobstructed (electronic) view of the tower from both places. But, effective distance is usually more related to obstructions and terrain than to simple distance. (3 watts vs .6 watts probably won't matter much if you're inside a cave!) Also, the protocols themselves use very sensitive clocking to assign your phone call to specific timeslots (in the case of Nextel/iDen), so there is usually an upper limit to the distance that your phone will operate from the transmitter. Digital cellular protocols are not designed for the wide-open spaces of Montana. Analog services work much better there!.

Please note that the links Kevin provoded are for external antennas or amplifiers designed to be placed outside in a area of sufficient signal strength.

[Jack]

I stumped the master... wonder what the prize will be for that (LOL just Kidding Kev)

So from the Anonymous post it would be safe to say doube the distance?

what is the average distance for a cell signal to go?

Jack

Jack,

The 'average' distance for a cellular signal to go is from your phone to the nearest tower. (Sorry! Couldn't resist.) And I just gave you theory. Your results may (might! probably will!) differ.

DIGITAL cellular systems are engineered for a tower spacing of between 5 and 8 miles without regard to traffic or terrain. In urban areas where higher traffic is expected, the towers may be much more numerous. Likewise, in mountainous areas, towers may have to be spaced differently.

Having said that, I have had my cellphone (Verizon StarTac) working towers over 20 miles away (From the top of a mountain in the Adirondacks I was billed for a call from Vermont -- which is some distance as the crow flies but certainly 'visible' with a good pair of binoculars from where I was.) Likewise, I have worked towers on Long Island while standing in Mystic Connecticut. I also know people who can use a cell phone from their boat about 10 miles off shore.

In general, analog signals will be usable at a greater distance -- although their clarity may suffer. Higher power is better than lower. An excellent antenna is required. 800MHz signals will be slightly better than 1900PCS signals over distance -- 800 MHZ is not as affected by smoke, haze, rain, or fog.

Remember, that you need unobstructed 'electronic visibility' to the tower for maximum range -- hills, buildings, trees don't help. The Earth's horizon plays heavily into this. The higher the tower -- or the higher you are -- the more likely you are to 'see' the tower. Most cell towers are 200 feet or less -- and possibly 'aim' their signal downward -- since they are trying to keep the signal on the ground. The older, rural, probably analog towers may have been designed for a wider field of view.

Also consider, that according to published reports, US spy satellites can 'hear' cellphone conversations. They orbit between 100 and 400 miles (supposedly) overhead!

[KevinJames]

Well, whoever you are, you sure know the technical field of radio transmission. So let me ask, what is your take on the "boosters" that are mentioned such as the one on this thread.

I wonder what the atmosphere would look like if we could visibly see all the radio tranmissions on all frequences from all devices including microwave ovens, cell phones, TV and radio, satellites etc.

Kevin,

NASA (I believe it was -- or a university doing research for them) just published an article that says the universe would be a light beige if all of the radio signals were to appear in visible light. I don't know the details or how they came to that conclusion...... So we can start there. You would be wandering around inside a light beige electronic fog! I'm not sure I'd want to know!!!

I wondered how long it would be before 'boosters' entered this thread! I have followed that discussion here and elsewhere for some time. Everybody and their uncle seems to want a better cell signal!!!

First, let me say that signal boosting is NOT an urban issue. Small handheld cell-phones work quite well where signal strength exists. For those people getting bad INDOOR reception, I would suggest an outdoor, highly directional antenna on their roof. The cheap stick-on 'boosters' are a waste of time and do not work.

Secondly, active repeater bi-directional area amplifiers (your buddy from Trinidad!) are not new. They have been around for sometime. They are indeed used in places like subways, passenger tunnels at airports, malls, etc. They are NOT cheap and are not intended for amateur (or even mobile) installation -- since to work correctly the antenna has to be aligned properly and power outputs have to be adjusted.

[[ Idea -- as the lights go on in his head: Why don't all these people who live in bad signal areas and whose zoning boards won't allow cell towers all get together and buy one of these repeater systems for communal use. They could install it on a convenient flag pole (roof!?) and provide service to their neighborhood. I see a proliferation of small, neighborhood subcells, much like the WiFi model being proposed by some souls. (Hey! Kevin. How much money you got to invest in such a scheme? What would the business model look like?) ]]

The SmartTalker unit referenced in your thread appears to be a mini-version of a BDA. It looks like it picks up the phones' signal via a small coil and passes it via the electronics to the outside antenna. It probably works. I don't see the price. You might be better off with a better phone than spending money on an amplifier. I can see why it would be popular in South Dakota. (How wide spread is digital service in rural South Dakota? Where you would really need the boost? So it may only be doing analog there -- and analog boosters are already really common.) I would not think it would sell well in New York City -- and amplifying a single cell phone to the detriment of others nearby would surely lead to network problems -- if not FCC issues -- in that environment. It does not appear to be a 'hand held' unit (cigarette plug, external antenna) so these people who want to walk around while talking might have problems. As would those who want to carry it in their pocket.

I do not know the legal status of a BDA. Do the units installed at malls etc have to be licensed or registered with the FCC? With the carriers? I did not see an FCC (or Canadian -- they appear to be Canadian) registration statement at SmartTalker. But ANYTHING that generates RF in the United States must be licensed or registered with the FCC under some regulation part or service. I would be very surprised if a device which generated multiple WATTS of power in the CELLULAR or PCS frequencies -- and which had the potential to cause real havoc to those services if mis-used (remember when linear amplifiers were being used on the old Citizens Band! remember the sometime argument about the cell 'zappers' supposedly installed in some restaurants and theaters?) -- could be used as casually as many people here imply. Consider that the phones themselves -- each and every one -- has an FCC registration and are legally LICENSED (via the carriers master license) to operate in the US (and in most cases by extension in Canada).

It would be interesting to hear more from the dealers who spoke up on these threads..... I would feel a whole lot better about the things if they were being sold at Radio Shack and at the carrier's stores.