Sprint PCS..why no 800mhz ??????

From Ryasvy Research: CDMA is a spread apectrum technology that uses different "codes" for spreading signals accross a certain ammount of radio spectrum. In addition to the spectrum being reused in every cell site for capacity purposes, an added advantage of spreading is that the radio signal is more immune to signal fading effects, since fading is specific to certain frequencies, and the frequencies do not all fade together. GSM, however, is also a spread spectrum system and has the same advantages attributed to CDMA.

wyldekard: i am curious to know what in your post you think contradicts what I have said. You have said that "the generally accepted voice channel frequency band in North America is 200-3200 Hz" which does't seem to disagree with me (1khz = 1000hz).

I am not saying that GSM is better than CDMA here. I am simply saying that they are both spread spectrum technologies. When you say that I come off like a zealot for saying that GSM is a spread spectrum technology, you obviously imply that spread spectrum is desireable and therefore come off like the 1000s of CDMA zealots in these forums. I have not said anything about GSM being better than CDMA in this topic - not even close. In fact, I have said that CDMA has an inherent advantage over GSM in the soft handoff. When I brought up that GSM is indeed a spread spectrum technology, I did so to correct an error where someone had said that spread spectrum technologies have the advantage of the soft handoff. I wanted to make it clear that this was inherent in CDMA-style systems not spread spectrum systems. You have called me a GSM zealot for telling people about an advantage that CDMA has over GSM. That is truely interesting.

GSM is a spread spectrum technology.

EDIT: What makes CDMA a spread spectrum system? I think that someone should define what they are talking about. Someone that disagrees with me has to say what makes CDMA a spread spectrum system and by definition makes GSM a non-spread spectrum system. Hint: It's not seperating calls by code and it's not having multiple calls using the same spectrum at the same time. This is what needs to be answered and no one has. I have given the definition used by the US gov't, but you don't seem to like that definition.

 

I have no clue how this disagrees with me, but I thank you for your mature responses. GSM doesn't have 8 timeslots per second. The timeslits are much smaller than 1/8th of a second, but when you combine all of the timeslots that someone would use it would come out to 1/8th of the second's bandwidth if the person used the entire second. CDMA does handle data differently than GSM, but it is because CDMA has all network access going over the same spectrum at the same time. If I made some absurd/obvious remakes here it is because I don't see you disagreeing with me.

 

Northform,

3200 Hz is 3.2 kHz. Three thousand two hundred Hertz is Three point two kHz (1kHz = 1000 Hz). Not 30 kHz as you said and I quoted in my response. So you see, what I wrote does contradict and correct your assertion.

I based my statement regarding your zeal, penchant for the type written word, and lack of verifiable reference on all your posts, not just the ones in this thread, and I believe it to be true. I should have been more specific as to what I was referring to and for that , I apologize. Perhaps you should go through all you have written, in all threads, and assume a neutral third person viewpoint. If you do this, to what I refer will become readily apparent.

You are entitled to your opinion and to present it in this forum as are others. Freedom of speech is something that I believe in and I have personally fought in war to preserve for this country. However, if it is your goal to teach, enlighten, or influence you may want to revise your methodology. Or perhaps you enjoy the argument for nothing more than the argument itself.

 

What's amusing is that I have yet to see a logical explanation stating why GSM is Spread Spectrum as Northform claims. Can you please give us an explanation of how GSM is spread spectrum? Can you explain this the way I explained it is not? This will be interesting.

However, here is a good tutorial for you...
http://sss-mag.com/ss.html

 

Ohh Verizon just dropping the Tri-mode idea, thats all...Dual Band governs your soul. MWAHAHHA

 

My $0.02...

TDMA: TDMA, or Time Division Multiple Access, is a digital alternative to the analog AMPS, or Advanced Mobile Phone System, cellular service. In January 1989, the US cellular industry accepted TDMA as the standard for digital cellular communications, even though it did not meet the requirements set forth by the UPR. TDMA works in a method similar to network packet-switching. It allows a cellular operator to divide the signal into short segments, allowing different conversations to "take turns." This allows three times as many people to use the system than amps. However, since TDMA is NOT spread-spectrum technology, available spectrums must be divided up for separate channels.

CDMA: CDMA, or Code Division Multiple Access, is another digital alternative to the analog AMPS (Advanced Mobile Phone System). CDMA was introduced by Qualcomm three months after TDMA was accepted as the standard. After two years of testing, CDMA was finally accepted as a second standard. CDMA works under a principle that has been used in military satellites for decades. Each conversation is granted a certain code - many conversations can be sent over the same spectrum at the same time with the receiving units decoding which information is directed to them. This is often compared to discerning a conversation in one's native language in a jumble of conversations in other languages. CDMA allows 4.4 trillion of these codes, assuring that different callers on different systems can use the same spectrum at the same time. CDMA utilizes spread-spectrum technology, meaning that conversations are spread across wide segments of the cellular broadcast spectrum. This helps avoid problems in busy areas and in hilly areas where reflected signals can cause problems.

Spread spectrum technology is also the means by which codes can be attached to communications. Each bit is expanded into some number of "chips." Thus, data transmission requires much more bandwidth, requiring much of the available spectrum. Many conversations can be transmitted over the same spectrum, however. The transmitter multiplies each bit by a "key" and transmits the multi-chip result. The receiver receives these chips as well as those of all other conversations transmitted over the spectrum. The receiver multiplies this combined signal by the appropriate key, takes the sum, and is able to determine which bit is appropriate. Because different signals can be transmitted over the same spectrum, CDMA allows 10 to 20 times as many conversations to occur on a system than AMPS. CDMA technology nearly eliminates many common cellular problems related to overcrowding, such as busy signals, dropped calls, and cross-talk. Also, CDMA's voice encoding allows for the reduction of background noise., CDMA transmission occurs at power levels 1/25 to 1/1000 those of AMPS or TDMA. This allows lighter portable phones with longer battery life.

And Sprint did not choose to go only 1900MHz just because. There is a VERY good reason. Reason being is that any carriers in the cellular band (800MHz) would HAVE to have in AMPS in place as well (according to the FCC), however if you run a PCS network (1900MHz) you don't need AMPS (again, according to the FCC). Running 800MHz: 1) costs more 2) requires a lot more spectrum. Sprint just built and utilizes a 1900MHz network because they don't want or have to spend the money on AMPS.

More fuel to the flamewar...