Questions tagged [telecommunications]
The telecommunications tag has no usage guidance.
191
questions
1
vote
1
answer
30
views
expected dwell time
I am trying to calculate the dwell time of a mobile user in a UAV coverage. So if \$x_\text{start}\$ and \$y_\text{start}\$ are the initial positions and \$x_\text{end}\$ and \$y_\text{end}\$ are the ...
- 11
0
votes
0
answers
25
views
Exercise on PPM modulation bit rate
A digital communication system uses N=15 identical routes. The modulation used is 2-PPM. Calculate the value of $$ \varepsilon_b/N_0 $$ on the exit from the first route so that a final error ...
- 11
5
votes
3
answers
826
views
Telecom cables for power transmission
Summary: Can I use abandoned telecom wire bundles as a 3-phase neutral?
Our campus currently has underground AC cables supplying 2 legs of 3 phase wye power to a remote (50 ft away) building. There ...
- 63
0
votes
0
answers
16
views
Are LTE-M or NB IoT Sim modules (eg from simcom) carriers restricted?
I am currently planning to build a board which will have to use LTE-M or NB-IoT technology due to their low consumption and because I do not need large data bandwidth. The targeted region is Africa.
I ...
- 21
-2
votes
1
answer
62
views
Was there ever a protocol to send profanity censorship tones out-of-band over television, so that viewers could turn them off? If not, why not? [closed]
These days, in the Western world, closed captioning is delivered out-of-band, so the captions are not actually part of the video itself, allowing viewers to turn them off if they are not desired (...
- 97
7
votes
6
answers
5k
views
Ethernet port as a signal generator
I was wondering if it's possible to turn a PC into a signal generator through the ethernet port (or at least an amplitude-modulated sine generator). I specifically care about the ethernet port since ...
- 141
-1
votes
1
answer
82
views
Data rate for an ASK modulation [closed]
A telephone line with a bandwidth of 3 kHz and an SNR of 6 dB. I am asked to calculate the maximum bitrate on this line and the error probability, knowing that ASK modulation is used.
For ASK ...
- 27
1
vote
1
answer
29
views
Why Phase1 GSM is mentioned to be a 3GPP release?
In some references such as Wikipedia (although wiki is not a reliable reference), GSM phase 1 is mentioned one of 3GPP releases while 3GPP itself is founded in 1998/1999 while GSM Phase 1 is ...
- 412
1
vote
2
answers
109
views
What component could be
I have a VDSL telephony socket with some electronics in it. I reverse engineered the PCB, but there is one component I cannot identify at all. Look like a 0.25W TH resistor, light-blue body and a ...
18
votes
3
answers
3k
views
How does a UK analogue telephone detect that the caller has hung up (disconnected)? [closed]
Scenario
This is a question regarding the design of UK analogue telecommunications equipment and the consequent design impact that is necessary for a router duplicating those signals. It is asked so ...
- 281
0
votes
0
answers
20
views
Noise in mm-wave initial access frameworks
I have a doubt about Initial Access (IA) procedures in mm-wave system.
In most papers I have read (see e.g. Initial Access in 5G mm-Wave Cellular Networks), most of the alignment procedures assume ...
- 101
2
votes
2
answers
448
views
Why do shift registers (LFSR) use the initial state "all 1"?
In all books about information coding theory, scientists describe shift registers of various configurations, but they always use the initial state "all 1" in any configuration and any bit ...
- 21
0
votes
2
answers
183
views
How to manage multiple devices connected to the same antenna?
I'm planning to connect an SDR in 'parallel' to a modem used to transmit and receive a radio signal on 2.4/5.8 GHz.
The SDR that I want to use is the HackRF one, which can receive up to -5 dBm in ...
0
votes
0
answers
83
views
Intersymbol interference on PAM Trasmitter
I would like to simulate on Matlab a PAM signal which, travelling on a time-dispersive communication channel, contains intersymbol interference (ISI).
I have 'built' the transmitter by generating:
8-...
- 473
0
votes
0
answers
92
views
Devices to measure RSSI and/or AGC
I need a way to measure the strength/power of a signal coming from an antenna, 2.4 or 5.8 GHz frequency. Is there any off-the-shelf device that can measure such property? Ideally I would want the ...