| Subject | Date Asked |
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| Satellite internet in India | 11/6/2009 |
Q: I am looking for 2 way mobile land based satellite internet service in india. do you have any info ...
A: Many thanks for this question. Regarding satellite internet in India, I don't personally get ...
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| satellite communication | 10/20/2009 |
Q: How to calculate sun outage for a place
A: Many thanks for this question. Unfortunately it's much too complicated to describe the process ...
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| Roll Off Factor... | 10/5/2009 |
Q: Please tell me that what would be the symbol rate which i can configure in my modulator for 6Mhz ...
A: There is not really a fixed relationship between the roll-off and the spacing factor in the way that ...
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| Roll Off Factor... | 10/1/2009 |
Q: Please tell me that what would be the symbol rate which i can configure in my modulator for 6Mhz ...
A: Yes, what you have stated is exactly the case. BUT there is an important clarification here. It ...
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| Roll Off Factor... | 9/29/2009 |
Q: Please tell me that what would be the symbol rate which i can configure in my modulator for 6Mhz ...
A: Really the issue depends on what ISRO mean when they allocate you 6 MHz. Do they allow a guard-band ...
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| FEC | 9/28/2009 |
Q: In our Uplink, we are changing FEC 3/4 to 5/6,I know advantage of FEC,but can you explain me what ...
A: When you change from rate 3/4 to rate 5/6 FEC you are reducing the amount of coding (i.e. before you ...
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| Roll Off Factor... | 9/24/2009 |
Q: during symbol rate calculation, we consider Bandwidth=1.28*Symbolrate where the roll off factor = ...
A: I am not familiar with that calculator, but I took a look at the page you indicated. For each of ...
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| Latitude & Longitude | 9/19/2009 |
Q: I want know about Latitude and Longitude,Plz explain my question? sanat
A: You ask a very general question, so I don't know if you were really looking for something more ...
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| Roll Off Factor... | 9/17/2009 |
Q: during symbol rate calculation, we consider Bandwidth=1.28*Symbolrate where the roll off factor = ...
A: Sorry it's taken me a while to answer but I've been very busy this week. The 3dB Satellite ...
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| Roll Off Factor... | 9/14/2009 |
Q: during symbol rate calculation, we consider Bandwidth=1.28*Symbolrate where the roll off factor = ...
A: The roll-off factor of a digital filter defines how much more bandwidth the filter occupies than ...
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| Antenna | 9/14/2009 |
Q: In earth station antenna, there are two categories: a) Cassegrain b) Gregorian I want to know that ...
A: Cassegrain antennas (where the subreflector is a hyperbola) are generally more popular for ...
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| FEC | 9/7/2009 |
Q: I know why we are using FEC.Plz tell me why we are using 3/4 and 5/6 etc.what the means of 3 and 4 ...
A: Many thanks for your question and I apologise for the short delay in answering. In any digital ...
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| carrer options in satellite communications | 9/6/2009 |
Q: good evening. i am parnita and im currently doing b.tech degree in electronics and communication,4th ...
A: Many thanks for your question. The field of satellite communications is a really interesting one ...
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| C/N | 9/2/2009 |
Q: I was trying to calculate downlink C/N for our C band downlink freq.To find downlink C/N i used the ...
A: Many thanks for your question and I apologise for the short delay in answering. There is a small ...
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| Link budget | 5/13/2009 |
Q: I doing a link budget where I have the SFD (dBW/m2) needed to saturate the satellite Transponder. As ...
A: Many thanks for your question. The formula you quote for SFD is correct; it correctly describes ...
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| antenna | 5/10/2009 |
Q: what is the difference between than mesh and solid antenna, and we can use mesh in Ku band or solid ...
A: Many thanks for your question. Electrically there is not a great deal of difference between mesh ...
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| Sidelobe mask and off-axis EIRP | 5/7/2009 |
Q: As a follow up to your response to above, usually the side lobe pattern is given as: 31 - 25 log10 ...
A: Many thanks for your question. Antenna sidelobe gain and off-axis EIRP masks are an attempt to ...
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| Link budget | 4/14/2009 |
Q: Definition & explanation required that used in link budget of Satellite communication (VSAT), i am ...
A: Many thanks for your question. There is a good introduction to Link Budgets on my "Satcom Online" ...
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| Buying and using Satellite Bandwidth. | 3/23/2009 |
Q: I'd like to say in advance how I really appreciate you taking the time to answer my question. I am ...
A: Many thanks for your question. I'm sorry for the small delay in answering it. Your question is an ...
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| Affect of eclipse season on geostationary satellites. | 3/14/2009 |
Q:
A: Many thanks for your question and I'm sorry for the delay in answering it. Geostationary satellites ...
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| satellite internet | 3/11/2009 |
Q: I planning to connect to the Internet via VSAT. But I was told that it's not allowed in my ...
A: Many thanks for this question. Yes indeed, there are satellite phones which (at a price, often ...
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| Antenna | 3/11/2009 |
Q: what is the difference between 31 - 25.log(theta) dBW and 29 - 25.log(theta)? Can you explain ...
A: Many thanks for your question and I'm sorry for the delay in answering it. The formulas that you ...
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| Choice of uplink & downlink frequency | 3/9/2009 |
Q: Why is the uplink frequency always lesser than the downlink frequency ? although this question has ...
A: Many thanks for this question and I'm sorry for the delay in answering you. The answers which ...
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| satellite communication | 3/8/2009 |
Q: in radio link design,I'd like to calculate the effeicency between certain satellite and associated ...
A: Many thanks for your question and I'm sorry for the small delay in answering it. In order to ...
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| Regarding sun outage | 3/8/2009 |
Q: Sir , What do you mean by Sun Outage ? Where it affect highly either in C band or Ku band ? Do you ...
A: Many thanks for this question and I'm sorry for the delay in answering you. I've changed this to a ...
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| the disadvantages of satellites | 3/7/2009 |
Q: what are the disadvantages of satellites?
A: Many thanks for this question and I'm sorry for the delay in answering you. Like all communications ...
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| satellite communications | 3/6/2009 |
Q: I am a regular reader of your question and answers blog. I would like to ask you some important ...
A: Many thanks for your question and I'm sorry for the small delay in answering it. You say that you ...
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| TWTA in satellite | 3/3/2009 |
Q: in space segment we mostly use TWTA rather than SSPA. WHY
A: Many thanks for your question and I'm sorry for the delay in answering it. Both TWTAs and SSPAs are ...
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| geostationary orbital satellites | 2/27/2009 |
Q: what is the role of goestationary orbital satellites in international organizational communication
A: Many thanks for your question and I'm sorry for the small delay in answering it. I don't fully ...
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| about satilite | 2/26/2009 |
Q: hai, i have small doubt about satellite coverage.ie)howmany satellites are required to cover the ...
A: Many thanks for your question. I've changed this to a public answer, because I don't answer ...
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| Off-axis EIRP | 2/26/2009 |
Q: I am looking at link budget and in particular the off-axis EIRP I have to respect in compliance with ...
A: Many thanks for your question and I'm sorry for the small delay in answering it. I don't think ...
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| Terms | 2/25/2009 |
Q: plz tell me the difference b/w CNR, SNR, Eb/no , Es/no in detail
A: Many thanks for your question and I'm sorry for the small delay in answering it. I've changed ...
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| Satellite Communications | 2/19/2009 |
Q: Please tell me how to find the interference caused in the Outbound signal of the hub? We do not know ...
A: The situation you describe can be difficult to analyse and it's not possible within the scope of a ...
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| Received signal strength | 2/11/2009 |
Q: good evening... i would like to ask for the formula given only the equipment's specifications. is ...
A: Many thanks for your question. I've changed this to a public answer, because I don't answer private ...
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| encoding | 2/9/2009 |
Q: Sir , What is difference between analog and digital encoding. could we get a analog signal after ...
A: Many thanks for your question and sorry for the short delay in answering you. I've changed this to ...
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| querry about units | 2/9/2009 |
Q: what is the difference between dbi, dbd ,dbm and dbw. I meant which unit we should use in link ...
A: Many thanks for your question and sorry for the short delay in answering you. Getting to grips with ...
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| Satellite Communication | 2/7/2009 |
Q: why we use HPA instead of BUC for higher data rates/what results are achived by more watts in HPA. ...
A: Many thanks for this question. The decision as to whether to use a BUC (with an integrated HPA) or ...
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| Downlink EIRP | 2/4/2009 |
Q: I would like to know how can I calculate the downlink EIRP if the C/N is available. If I am not ...
A: Luis Emiliani already answered this same question here: ...
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| ku-band uplink/downlink frequency | 2/4/2009 |
Q: how can one convert from ku-band uplink frequency to downlink frequency? Just as 2225MHz is the ...
A: Many thanks for this question. The difference between the uplink and the downlink frequency in a ...
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| SATELLITE INTERFERENCE | 1/9/2009 |
Q:
A: Many thanks for this question. Unfortunately there is not a straightforward answer to your ...
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| satellite communication | 1/6/2009 |
Q: why in satellite communication uplink frequency is lesser than downlink frequency?
A: Actually you have this the wrong way round! Normally it is the case that the downlink frequency is ...
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| LST 5 Pattern Advantage | 11/5/2008 |
Q: I'm competant with Satmaster Pro link budgeting but have come across a problem using intelsat's LST5 ...
A: Since the LST5 lease transmission planning software is proprietary to Intelsat I would suggest that ...
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| Beacon signal in GEO satellite | 10/29/2008 |
Q: Can you please define what is a beacon signal? why it is used? and what is the typical EIRP ...
A: A satellite beacon is a fixed-frequency, fixed power, unmodulated carrier which is radiated by the ...
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| How to find G/T of antenna if everything else is provided - Link budget | 10/23/2008 |
Q: i got to design the ground station antenna. I need atleast to figure out G/T of the station. I ...
A: The question you ask is rather a complicated one, and I don't really have time for a very detailed ...
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| Maneuvering | 10/20/2008 |
Q: Good day. Can you please explain what is maneuvering in satellite systems?Thank You
A: Satellite maneuvering (manoeuvering in "British" English!) is the use of (usually) on-board ...
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| Transponder capacity | 9/26/2008 |
Q: I would like to ask you a question regarding how many E1 link could be provided by 1 transponder ...
A: Unfortunately the situation is not as simple as you hope! There are two factors which determine ...
|
| satellite | 9/22/2008 |
Q: there is a disadvantage of sattelite is that there ie half second delay of communication between ...
A: I'm sorry but what you are asking is not entirely clear to me, but I *think* you are asking where ...
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| Link budget OBO | 9/18/2008 |
Q: I know that OBO is the output back-off for a satellite transponder . To my understanding it should ...
A: You are right that the output backoff point should represent the operating point in the ...
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| Band | 9/11/2008 |
Q: Do you have a chart that describes each satellite band by capability and limitation? Thanks, pls ...
A: I don't have a chart which describes what you are looking for, I'm afraid. There's lots of useful ...
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| PSD | 9/10/2008 |
Q: 1- please explain the concept of power spectral density in easiest manner & its use in link budget ...
A: 1) Re PSD, I already answered this exact point in your previous question so I won't repeat my answer ...
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| sat com | 9/9/2008 |
Q: please explain the concept of power spectral density & its use in link budget calculations
A: A modulated radio carrier has a power and a bandwidth. We can make link budgets in terms of the ...
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| SSOG and IESS | 9/4/2008 |
Q: I have a pretty broad question. Is the new name for SSOG now IESS? If not, generally speaking what ...
A: It's been a while since I worked on Intelsat standards! These two sets of documents are not the ...
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| Signal fading in inclined orbit satellite. | 9/3/2008 |
Q: I have an interesting problem. I have a 9.3m dish in Nairobi tracking is601 and it connects to a ...
A: Interesting questions get faster answers! The C/N is clearly lower than expected and this could ...
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| Signal fading in inclined orbit satellite. | 9/3/2008 |
Q: I have an interesting problem. I have a 9.3m dish in Nairobi tracking is601 and it connects to a ...
A: Indeed an interesting problem. Do you have a link budget for the link? If you are only 2 dB from ...
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| communicating | 8/31/2008 |
Q: I hope you can help me (if not send me somewhere that can). I want to transfer programs that i have ...
A: Tony, I did a bit of Googling and the general consensus was that it's not possible using the USB ...
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| satellite | 8/28/2008 |
Q: what do you mean by satellite link designing? what type of satellite link? what is link budget?
A: Satellite link designing is the engineering "art" of determining the technical parameters of the ...
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| bandwidth vs Symbol rate and Data rate | 8/27/2008 |
Q: i have a video uplink and my modulatior/encoder has this readings Data rate: 5119800 bps Symbol ...
A: To give a general answer, one piece of important data is missing from your question and that is to ...
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| satellite communictaion | 8/22/2008 |
Q: what is roll of factor ?kindly define it in simple word ANSWER: Hello, I suppose that you are ...
A: Sorry that it has taken a little time to get back to you. Roll-off factor and symbol rate refer to ...
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| satellite communictaion | 8/21/2008 |
Q: what is roll of factor ?kindly define it in simple word
A: I suppose that you are asking about the roll-off factor of a digital filter? The roll-off factor of ...
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| antenna | 8/20/2008 |
Q: Sir tell me the main advantages of using CENTER FITTED and OFFSET FITTED antenna?Which one is ...
A: Sorry for the delay in answering your question. The main advantage of antennas with an offset feed ...
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| 110020 | 8/18/2008 |
Q: Could you please tell me that why we use cassegrain antenna in bigger antenna's application in ...
A: Cassegrain antennas (where the subreflector is a hyperbola) are generally more popular for ...
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| satellite communcation | 8/14/2008 |
Q: what is the rain effect in satellite communication transmission system ? have a nice day
A: Rain (also snow, hail and ice to varying degrees) in the satellite communications path will cause ...
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| satellite communication | 8/13/2008 |
Q: why the uplink frequency higher than downlink frequency ? have a nice day
A: I have always understood that the reason is because the path attenuation (loss) due to rain ...
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| beacon | 8/9/2008 |
Q: could u please explain to me the meaning of a BEACON. i am new in the field of vsat engineering,and ...
A: A beacon is a fixed-frequency unmodulated carrier transmitted by the satellite for reception on the ...
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| how to install micrwave (v-sat) | 8/8/2008 |
Q: please i would like to know the practicl step-by-step in installing vsat and microwave communication ...
A: The reply would be too long and complex to give a detailed answer here, but this training website ...
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| Anteena | 6/7/2008 |
Q: (1)what is the main roll of Antenna ? (2)Why we use different sizes of antenna ? what is the logic ...
A: (1) Not sure what you mean by this question - please send a follow-up to explain in a bit more ...
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| Question | 6/3/2008 |
Q: Sir,I work in satellite ground segment. Please tell me how to assign the EIRP to the customers with ...
A: Unfortunately there is no simple answer to this question. You can think of the transponder as ...
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| Bandwidth | 6/1/2008 |
Q: What is the relation between symbol rate & Bandwidth ?
A: The Nyquist bandwidth is the smallest theoretical bandwidth that can be used to receive the signal, ...
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| Amplifiers | 5/31/2008 |
Q: why TWTA is called as a broadband amplifier & KPA is called a narrow band amplifier
A: A klystron power amplifier (KPA) is a tuned device in which the amplification is achieved through ...
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| vsat | 5/28/2008 |
Q: Is It possible to capture the C/N value at the remote end instead of Hub? ANSWER: This will depend ...
A: Except in some limited and rather specific cases, you have to use different frequencies for uplink ...
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| data rate and SSPA size | 5/27/2008 |
Q: how can i choose data rate with SSPA size... how can we calculate beacon frequency of satellite
A: It's rather more complex than your question implies. You need to know the satellite parameters ...
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| Internet access. | 5/24/2008 |
Q: Between Ku-band and C-band which is better as a backhaul/gateway for Mesh Network.
A: If the link is engineered properly - i.e. sufficient Eb/No to support the required BER and enough ...
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| combiner | 5/23/2008 |
Q: the output of modems connected to combiner.then output of combiner is connected to up converter. ...
A: The upconverter (block upconverter or BUC) has a single RF input port and a single RF output port. ...
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