What is the relationship between c/i,rxqual and frequency reuse pattern in the gsm network?
85370
C/I = (r/(D-r)) ^ -4\n\nWhere C/I is the co-channel interference protection ratio, r is the cell diameter, D is the distance between similar cells in adjacent patterns.  See equation 9-6, page 527 of the reference in "Source(s)".
10500
I think the previous answer is geared towards channel allocation and not bit rate vs bandwidth.  I will try to clarify the issue.\n\nFirst, you must understand how FM works and how a digital signal converts to FSK (frequency shift keying).  Therefore I will use a simple example.\n\nEach bit takes up some frequency.  For example, the bit '1' could take up 5 Hz carrier frequency on the bandwidth spectrum and '0' could take up 6 Hz on the bandwidth spectrum.  Therfore, there is a seperation of 1 Hz between bits.  \n\nIf I send a '1' followed by a '0' then on a meter I should see 5 Hz freqency and then a 6 Hz frequency back to back.  We could speed this up to infinity and therefore have these 2 frequencies transmitting all data at infinite speeds.\n\nIn the real world however, a '1' may fall around the 5 Hz frequency but not exactly on it.  It may be about 5 Hz.  Why around 5 Hz and not exactly on it everytime?  Because in the real world we have noise in transmission lines.  Noise can distort the frequency causing it to be a little less than 5 Hz or a little more than 5 Hz.  Imagine if the '1' bit is transmitted but on the receiving end it ends up receieved as 5.5 Hz.  What happens now?  It's not quite 5 Hz and it's not quite 6 Hz.  Noise caused it to move 0.5 Hz away from 5 Hz.  It is in the middle of 5 Hz and 6 Hz.\n\nNow the receiving end has to decide if this is '1' or '0'.  What are the odds the receiving end gets it right?  By slowing down the speed the 1s and 0s that are transmitted , you can hold steady the 5Hz or 6 Hz for that bit.  The faster you go, the less accurate the bit will fall exactly where it should on the frequency.\n\nSo, what are some possible solutions?  Well, you can slow the frequency down or make the frequency seperation larger.  For example, make a '1' be 5 Hz and make '0' be 10 Hz.  Now you have 5 Hz seperation between bits instead of 1 Hz seperation.  Now if the frequency of 5.5 Hz is received, the receiving end can determine that this should have been 5 Hz.  It's highly unlikely it was originally transmitted at 10 Hz.  Therefore, the receiving end detects a '1'.  \n\nBut what have you lost by doing this increase in frequency seperation?  You have taken up more bandwidth.  Every cable has only so much bandwidth and if you have several channels on a cable all transmitting at the same time, you need to limit the amount of bandwidth each channel takes up or you will run out.\n\nSo, therefore, since most companies don't want to backdown on speed to the consumer (you), then they upgrade their technology (i.e. cables) to higher bandwidth cables such as fiber optic cables.\n\nI hope this helped.  Others, please feel free to expand on this topic.  I've only discussed FSK modulation.  Other techniques such as PSK, ASK, QPSK, bit stuffing, NRZI, CRC, and FEC codes can improve bit rate over channels.\n\nYou can read more about bandwidth limits.  Shannon and Hartley came up with a theorem which still holds today and is used quite extensively.  I even know someone who worked with Shannon at Bell Labs back in the day.  Shannon's theorem is C = BW*log2(1+S/N) where C is the channel capacity in bits per second,  BW is bandwidth, S is the signal power and N is the noise power.\n\nWF\nTelecom Engineer
495154
a wireless communication standard.
1050435
if u r using cordless telephone with 2.4 ghrtz  in your home u will face this problem bcause your router and phone both working on same frequency you have two option  change the frequency  of your router by calling  tec.support or changet the phone
1179292
Here is one link: \nhttp://nis.gsmfc.org/nis_factsheet.php?toc_id=140\n\nDo a search on the search bar below and find more. And put some effort urself into your homework :)
800437
I think that signal comes out of Denver.  I have had several and enjoy the accuracy.  Forget what that other guy said.  All of mine have had a two minute synch time.  If you fail to get a grip on the signal in that amount of time, you have to reset and start over.  You may have to try different placements.  I don't know why but once you get a synch the unit won't lose it if you move it around, as much as it looses it on initializing.
207471
Go here for an automatic HJT analysis:\nhttp://hjt.networktechs.com/
255636
The communication of signals is accomplished differently.   To allow many people to communicate at the same time, without interfering with one another, different modulation methods are used.  CDMA is "Code Division Multiple Access" and communication is separated by using different orthogonal code sequences. In both CDMA and GSM phones, your voice signal is first turned into a digital sequence of "1" and "0" symbols.  In CDMA, this sequence is convolved with a unique code (the spreading code) and sent using a large frequency space (bandwidth).  In TDMA (Time Division Multiple Access) which is the modulation format used in GSM phones, your digital sequence is sent without interference by sending your sequence at a time when other transmitters are not on the air.  In this way, GSM uses time, to temporally separate signals.  Both GSM and CDMA phones use multiple channels to further expand the number of users that can be 'on the air' without interfering with each other.  The use of multiple channels is called FDMA or Frequency Division Multiple Access.
1184762
When two modems are communicating over a phone line, they use audio signals at specific frequencies as the "0" and "1" of binary code.  That noise you hear is the rapid alternation of audio signals between those two frequencies.  They do this since phone lines were designed to transmit audio frequencies, so the modems use audio frequencies to communicate in binary form.\nIt's that simple.
776439
I have no idea.  Call the operator to find out.\n\nCoach
170564
try\n\nhttp://www.radioreference.com/modules.php?name=RR&ctid=28
895782
Xc=1/2π f C\nAs you can plainly see, capacitive reactance is a function of both capacitance and frequency.\nIf you work the arithmetic, you will see that the reactance decreases as capacitance increases while freqency remains stable, thus is inversely proportional.\nYou can work through the various permutations and chart the various relationships.
40129
That's a big subject.  Analog or digital? U.S., Europe, Japan, Germany, Scandanavia, Germany, UK?  All use different systems.  Most use some form of spread spectrum technology, which makes them resistant to jamming.  A good reference is Peterson, Ziemer, and Borth, "Introduction to Spread Spectrum Communications", ISBN 0-02-431623-7.\n\nAlso, see http://en.wikipedia.org/wiki/Cell_phone_jammer\n\n\nFor U.S., "The FCC has fielded enough queries about the legality of cell phone jammers that it issued a notice last year. In it, the agency warns that jammers violate federal laws that broadly prohibit interfering with licensed radio spectrum. Owning, manufacturing, marketing, offering for sale or operating a cell phone jammer is punishable by an $11,000 fine and up to a year in prison for each offense, the notice states."\n\nFrom http://www.newhousenews.com/archive/story1a092200.html
1004300
Different reasons -- \n\n1.  Frequency separation.  Radio stations operate on different channels (frequencies) than CB radios for example.\n\n2.  Different locations.  You can operate on the same frequencies if the transmitters are located far enough away from each other.  Look how many "Channel 3" TV stations there are.  They're far enough away from each other so they don't interfere.\n\n3.  Different modulation.  FM and AM are types of modulation.  In the case of radio, they're also on different spectrums, but you could have the same frequency modulated differently and have minimal interference.\n\n4.  Digital transmission.  You can transmit information digitally over the airwaves and "multiplex" it such that it doesn't interfere with other transmissions (cell phones for example).
718103
First, about cellular generations. Having worked in the industry for a while, I have a narrower view what 1G, 2G, 3G, 4G, etc. mean. First 1G service was based on a TDM voice infrastructure -- built around class x switches and 64 kbps slots. It had data, but circuit switched over a 64Kpbs voice bearer.\n\nSecond, 2G service had the same switched TDM backbone, but added a true Data Bearer and a digital voice bearer. Data rates were still limited to the max 64kbps of a single time slot.\n\n2.5G added a packet bearer to the mix, still limited to 64kbps slots.\n\nThird generation (3G) changed the backbone slightly to allow a full T1 or E1 or J1 to be consumed by a data sub-scriber, but is still based on an ISDN style backbone. Sure you have packet switched data, but its carried over a traditional TDM backbone. There still a circuit voice backbone and while the data rates are high enough for VoIP, the latency of the data service is to great to base all of the "bearer services" on it, so you still have circuit voice, circuit data and packet data bearers.\n\nFinally, 4G systems will utilize a packet infrastructure rather than a traditional telephone architecture. Services will be horizontally layered on top of a proper low latency, QoS enabled packet switch (read IP) infrastructure. Gone will be the circuit voice and circuit data bearers.\n\nSo "G" has more to do with the infra-structure and less to do with the data rates. The data rates over the air are driven by the organization of the infrastructure and other than that have little to do with what generation they are.\n\nIn that sense, this NexTel trial is a 4G trial. BTW, I'm a participant in that trial. If folks are interested, I'll post some results that I might be able to share.\n- by NetGuy
448946
Rx diversity utilizes multiple antenna elements to provide gain in the receive path of a wireless system. \n\nFor example in a mobile wireless telecommunications system (cellular) RX diversity is used to provide gain and improve coverage. 2 receive paths (antennas lines etc...) are used on a cellular tower. The antennas are typically placed 10 feet apart at the same elevation on the tower (the further apart the antennas the more gain achieved, although after about 10 feet not much additional gain is achieved). Both receive the mobile signal, and the base station electronics then looks at both paths for the "best signal" (not exactly how it works, but in laymans terms it's close enough). This improves quality for the mobile, and typically yields @ 10db improvement in the link budget. It is effective in eliminating raleigh fading, and other signal impairments.\n\nThere is also Rx diversity used on the mobile side. \n\nTo achieve diversity, the receiver needs to have the capability of accepting multiple receive paths (two or more), and then either combining, or switching between the paths.
778142
The same one which you connect your telephone line to.