Satellite Communications - Satellite Communications - Industry

	AllExperts > Satellite Communications
	Search

About Luis Emiliani
(Top Expert on this page)

Expertise
Strengths - Satellite link design and analysis - Vsat network design and analysis - Propagation aspects for terrestrial and satellite links - ITU-R P recommendations Can not help with: - Questions related to TV receivers, TV kits, or specific networks such as DirecTV or DISH - Antenna pattern synthesis, RF MoM analysis, S-parameters.

Experience
My experience is in satellite communication networks and terrestrial microwave links.

You are here: Experts > Industry > Satellite Communications > Satellite Communications

Questions Answered By Expert Luis Emiliani
In Category Satellite Communications

Subject	Date Asked

satellite communication	7/8/2009
Q: how to calculate center frequency.How to convert RF range frequency into if range.What I know is for ... A: well, you have you have your answer right there: in order to determine the center frequency of your ...
link budgeting-Sat Master	7/7/2009
Q: I'm calculating link budget using Sat Master. My satellite operator gave me the leased bandwidth and ... A: In satmaster, depending on the version you use, you will find the bandwidth of the carrier, ...
satelite bandwidth	7/3/2009
Q: Cpuld you please answer me how to calculate a bandwidth for sat uplink I have tried BW=SR x roll-off ... A: the allocated bandwidth at the 3dB point of a carrier should be matching the values in the ...
Purpose of Pure carrier (Transmit CW)	7/1/2009
Q: Can you tell me the purpose of this option.Many thanks. A: the main purpose of that function is to aid in the fine pointing of the system using a spectrum ...
Output back off per carrier and downlink eirp	6/30/2009
Q: I am trying to do a link budget for SCPC VSAT network. In this how I can work out Output Back off ... A: there are two elements to this. the downlink EIRP can be calculated when you know the transfer ...
How to calculate PEB	6/28/2009
Q: I'm interested to know how to calculate PEB. For example, imagine a 72MHz transponder with x3 ... A: Well, if you understand that then you are halfway there. let's take a transponder of 51 dBw and 72 ...
Vsat link budget	6/25/2009
Q: Hope you had a nice vacation. I am trying to build a link budget for Ku Band Network of 50 ... A: well, it all depends on the type of system you purchase. a typical vsat system has a shared outbound ...
like to know the application of satellite to television digital and analog transmission	6/24/2009
Q: good sir, please i will like to know as a beginner about the application and explanation of ... A: geostationary satellites are perfectly suitable for broadcasting applications, due to the large ...
Vsat link budget	6/22/2009
Q: Hope you had a nice vacation. I am trying to build a link budget for Ku Band Network of 50 ... A: in terms of capacity : if you need 256K per site, you can say that the outroute or outbound carrier ...
Vsat link budget	6/20/2009
Q: Hope you had a nice vacation. I am trying to build a link budget for Ku Band Network of 50 ... A: in essence, the process does not change from 1 to 50 sites. it is still the same equation and the ...
Telecommunacation	2/17/2009
Q: 1 what is KU band and c band? 2 what is beam length of KU and c band ? 3. what is the beam width of ... A: ku, c, x, l, s all refer to the conventional (not the current ITU way) way of naming microwave bands ...
Apropiate Antenna Size for FTA reception	2/15/2009
Q: Luis: Hi.. I need your help in this.. I'm located in Ecuador South america Long. 79.54W Deg, ... A: i suggest you use these online tools http://www.satsig.net/linkbugt.htm ...
Modem	2/11/2009
Q: I would like to know, when designing a satellite link, how do we determine is an IF or L-band modem ... A: the main difference between 70 MHz, 140 MHz and L-ban interfaces is the maximum available bandwidth. ...
link design	2/9/2009
Q: Sir, Please tell me how to calculate a good link design of one single transpomder of 36 Mhz with ... A: the process is a bit too long and involved for this forum Nevertheless, i suggest the following ...
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: well, you're expression is not quite there yet as you are missing the bandwidth of the signal C/N = ...
Varying signal strenngth	2/3/2009
Q: 1.we are using two transponders on the same satellite, while one transponder is siganl strength is ... A: well, other than making sure that your installation is correct and that you are not operating at the ...
satellite communication	1/30/2009
Q: Sir,i want to inquire about adjacent satellite interference (ASI),like at which separation what ... A: this is not a simple matter. Adjacent satellite interference depends on where you are (your orbital ...
Link budget	1/29/2009
Q: we are experiencing problems in establishing a connection with the W6 satellite (having a 47dBW ... A: well, without all the carrier details and satellite parameters i can not provide a definitive ...
Modulation Technique	1/28/2009
Q: I just want to understand the modulation techniques in a different way!! I mean, i know that 8PSK ... A: let's go step by step. the bandwidth depends on various factors: modulation efficiency (number of ...
Lost Signal	1/24/2009
Q: What is the Satellite Signal Cable...as my tv screen tells me to check it. Where is it and which one ... A: sorry i took so long to reply. the satellite signal cable is the one running from the dish ...
look angle calculation	1/20/2009
Q: sir i wants to understand look angle calculation & its importance as i can't understand the same ... A: a very good source which you can find on the internet is this : ...
Satellite signal degradation due to snowfall	1/19/2009
Q: but can snowfall affects c band signal in atmosphere or it can only affects when it covers the ... A: Rain becomes a big problem when the wavelength of the signal is of comparable dimensions to an ...
BW optimization	11/5/2008
Q: is LDPC contribute in PEB reduction? thanks A: yes, definitely. whenever you find yourself in a sitatuion where your allocated power exceeds the ...
IF TO RF Clarifications	10/31/2008
Q: I have the following questions with regards to conversion of IF to RF, eventhough i have read ... A: if you are working in 70 or 140 MHz you can do two things 1. you convert to L band using an if to L ...
POLARISATION	10/21/2008
Q: WHAT IS THE METHOD TO DETERMINE POLARITY OF ANY UPLINK FREQUENCY, I.e IT WILL BE CIRCULAR OR LINEAR? ... A: in an ideal world, you select the polarization of your link depending on the surrounding systems ...
Satellite Receive Antenna	10/17/2008
Q: What is the noise level that the satellite receive antenna can be tolerated, does it depends on the ... A: The G/T or figure of merit of a receive system is a measure of how noisy the receive system is. the ...
SSPA and HPA	10/15/2008
Q: Can you tell me the difference between SSPA(Solid State Power Amplifier) and HPA(High Power ... A: no, a twt and a klystron are not the same thing. they are tubes, but the principles through which ...
SSPA and HPA	10/14/2008
Q: Can you tell me the difference between SSPA(Solid State Power Amplifier) and HPA(High Power ... A: in general the term HPA is used as a generic term covering all technologies (solid state, twt and ...
KU band satellite frequencies	10/8/2008
Q: I am in Saudi Arabia in Lobar. 2ND 50E(approx)I am using KU band offset dish.I installed my dish to ... A: perhaps you are pointing the antenna with the feed looking at the opposite polarisation?go to this ...
uplinking	10/7/2008
Q: If I’m using one RFT uplink to transmit on vertical polarization and receive on horizontal. Can we ... A: If you have an antenna with a 2-port feed (one port transmit, one port receive) you are fixed to ...
minimum Shift keying	10/3/2008
Q: Explain why minimum Shift keying is considered a constant envelope modulation technique. What is the ... A: phase-only modulations like BPSK, QPSK, and its variations such as MSK and GMSK are considered ...
polarization	10/2/2008
Q: hope you are doing great. We are in the process of building a new vsat hub and I was offered to ... A: the simple answer is no, you can not. if you intend to transmit in H your antenna has to have the ...
G/T measurement	10/1/2008
Q: For X band antennas, I would like to now how to make the best G/T measurement using the sun, the ... A: i think itu recommendation S.733 Determination of the G/T ratio for Earth stations operating in ...
primary metal for antennas	9/27/2008
Q: COPPER efficiency is also about 90% and it is a perfect conductor.why not parabolic dishes made of ... A: in part because of weight, in part because of the properties you are exploiting. conductivity is not ...
steerable beam	9/26/2008
Q: can this will effect the permanent scpc users due to footprint and to what extent (in terms of ... A: the main advantage of a steerable beam is the capability to track demand on the ground. considering ...
linearizer	9/25/2008
Q: Presently our services are going on without linearizer but now the work assigned to me to put one ... A: well the measurements that you need to make are the transfer curve of the amplifier (IBO vs OBO or ...
L BAND MODEM	9/21/2008
Q: i have used old IF FREQ MODEMS (52-88 mhz) of AGILIS and COMSTREAM but now we are using paradise and ... A: there are a coouple of important reassons favouring the use of l band modems 1. l-band devices ...
mesh antenna	9/19/2008
Q: this is sachin again can we transmit with mesh antenna effectively,kindly explain the difference if ... A: as long as the antenna is approved for transmit and receive operation, you can do so. note that ...
PLL LNB vs DRO LNB ?	9/10/2008
Q: What is the difference between the PLL LNB and the DRO LNB, pros and cons; when do I have to use the ... A: PLL stands for Phased Locked Loop, and DRO is dielectric resonator oscillator. PLLs are more stable ...
r f & if	9/9/2008
Q: 1-is there any specific reason of using 50 ohm termination in case of R F & 75 ohm termination in ... A: the split between 50 Ohms and 75 Ohms comes from the analysis of coaxial cables as transmission ...
antenna	9/4/2008
Q: as we know the large antenna has large gain but i believe it will also increase the noise floor then ... A: i apologize for my delay in answering. Large antennas are used mainly because of the benefits that ...
satellite question	9/3/2008
Q: which factor decides the RX dish size for diffrent BW to get good receive in global contour. kindly ... A: the receiver dish size is determined by various factors 1. the available EIRP from the transmitter ...
2 receivers on dish	8/31/2008
Q: I have two FTA receivers and one elliptical dish with four dual lnbs on it rather then running two ... A: i am not too sure of what your setup is, but i assume you meant splitters instead of switches, and ...
Dishes size vs Rate	8/30/2008
Q: I have the following link: Site A is My office uplink is 256 Kb/s, and 128Kb/s Downlink. I have a ... A: sorry for taking so long to answer. i am afraid there is no simple answer to your question. you can ...
satellite communication / interferance	8/28/2008
Q: i want to helpe me , im a teleport engineering in jordan media city , now there are a big problem in ... A: well. an interference problem is never easy to solve the first thing you need to do is identify the ...
Satellite Communications	8/27/2008
Q: sir can explain ka band up-converter with built in redundency switch A: an upconverter is a device that takes a signal (modulated or not) at a frequency A and translates it ...
regarding link budget...	8/25/2008
Q: .like i said if i have 6MHz bandwidth and i have to run single video channel on c band. what are the ... A: explain step by step a link budget is very long task, and i am afraid this forum is not suited for ...
Antenna	8/23/2008
Q: i want to know that, what is the relationship between EbNo and BER and what is the effect of ... A: EIRP is effective isotropic radiated power. without elaborating too much, it represents the ...
Antenna	8/21/2008
Q: i want to know that, what is the relationship between EbNo and BER and what is the effect of ... A: this is a good reference http://www.w1ghz.org/antbook/conf/Multiple_reflector_antennas.pdf in ...
VSAT	8/20/2008
Q: Kindly sir tell me the name of INTERNAL INTERFACES of BUC and LNB through which we connect BUC and ... A: well, the interfaces are not internal, are pretty much external. you connect the buc and lnb to the ...
Link budget	8/18/2008
Q: I want to know how to determine the HPA size from link budget result (the tool i'm using is LST5)? ... A: yes, the maximum information rate supported by a given configuration depends on the available SSPA ...
satellite communication	8/15/2008
Q: why in c band use mesh desh antenna ? have a nice day A: a mesh dish is just like a standard solid dish. of course it brings other mechanical features that ...
Questions about quantized phase modulation/multiple phase shift keying.	8/13/2008
Q: What is the fastest internet speed one can achieve using M-PSK [Multiple Phase Shift Keying] on a ... A: i am not really sure what you are looking for. however, i would like to note a few things. In the ...
Satellite uplink power in C and Ku band	8/12/2008
Q: Could you please clear this thing that either C band or Ku band require higher uplink power to fire ... A: this is not always necessary. most block-upconverters do have internal reference signals, and you ...
C and Ku-band equipments	8/11/2008
Q: I want to ask about the following cases: What are the equipments that i need to install a complete ... A: unfortunately, i can not give you detailed equipment choices here, because it all depends on the ...
satelite communication	8/9/2008
Q: why we use c band?and what is the major difference c band and Ku band?please tell me briefly. A: the main difference is the bandwidth and frequency of operation. C band is the name given to the ...
regarding downlink power	8/6/2008
Q: please tell me why the power output from TWTA at the satellite for downlink is more in ku band as ... A: i am not familiar with that particular satellite so i couldn't say why. it might be a design issue ...
Regarding downlink power	8/5/2008
Q: i want to know that, what is the relationship between EbNo and BER and what is the effect of ... A: i am not sure i understand your question. is your question why less power is needed in ku band for ...
IRD response	7/31/2008
Q: i just want to ask you a qustions about my work if you can give me an > idea: > > 1- if i transmitt ... A: in both cases you have interference, and in both cases you will se a degradation in the BER at the ...
Typical Carriers	7/30/2008
Q: I work in a satellite management center where we spend a lot of time resolving interference ... A: we'll, there is no formal database, but you can build one and with experience learn to recognize ...
Configuring Routers to modems	7/23/2008
Q: Please how can i configure my router to my modem? What are the things i will need to know in order ... A: the connection between the router and the modem could be by several means 1. you use a serial ...
Eb/No	7/18/2008
Q: If we measure Eb/no at VSAT's end.and if i check the same at Hub end what will be the difference? or ... A: it will all depend on how you design your link. you normally design to be some dB above threshold. ...
hooking up a cband 8ft satellite dish	7/17/2008
Q: hey I have a question about how to hook up this huge 8ft satellite I have in my backyard to a ... A: well i am not familiar with the brand, but in essence you need to: 1. make sure you have identified ...
Regarding Eb/No and FEC coding	7/14/2008
Q: i want to know that, what is the relationship between EbNo and BER and what is the effect of ... A: there are some tutorials on the web that can help you understand what it is all about. try these: ...
Regarding Eb/No and FEC coding	7/11/2008
Q: i want to know that, what is the relationship between EbNo and BER and what is the effect of ... A: the relationship between BER and Eb/no depends on the type of modulation selected. Actually, what ...
Eb/No for different service ?	7/10/2008
Q: How's about the minimum Eb/No value for a certain service ? For example, TVSC DTH in C band QPSK, ... A: yes, the IESS (not the SSOG) give you an idea of some intelsat standard services. what you are ...
Satellite Communication	7/9/2008
Q: if i want to uplink TWO TV Channels from same place , how do i initiate.. tell me what power of BUC ... A: well, your question is one that can not be answered without extra information what you are talking ...
advanced formula for PATH LOSS in GPS	7/8/2008
Q: I am a beginner of GPS.what is the complete formula for pathloss in GPS Satellite system. A: the path loss expression remains the same, regardless of the application. The expression is FSL = ...
Satellite uplink power in C and Ku band	7/5/2008
Q: Could you please clear this thing that either C band or Ku band require higher uplink power to fire ... A: the standards can be downloaded from the ETSI website. once you figure out the name of the standard, ...
Regarding Satellite orientation	7/4/2008
Q: You had mentioned in your answer that the difference between two satellites are 1,2 or 3 degrees. ... A: the main reason is to improve spectrum utilization. theoretically speaking, perfect devices will ...
Regarding Satellite orientation	7/3/2008
Q: You had mentioned in your answer that the difference between two satellites are 1,2 or 3 degrees. ... A: what do i say? simple: those satellites are sharing an orbital position. Look at ASTRA, Hispasat, ...
Satellite orientations	6/30/2008
Q: Could you please clear this thing that either C band or Ku band require higher uplink power to fire ... A: sorry for the delay in replying. I am not sure what you mean by orientation. certainly, the way you ...
Uplink and Downlink Modulation	6/24/2008
Q: I have seen one question regarding the FSK/FM Modulation. Some of the satellite operators use FSK/FM ... A: Both modulations you refer to have the advantage of being relatively insensitive to changes in the ...
polarisation	6/22/2008
Q: What is the exact definition of polarisation ? Which polarisation is better ? either linearly , ... A: The polarisation of an electromagnetic wave describes the position of the tip of the electric field ...
vsat	6/21/2008
Q: What are the standard regulatory practices to avoid inteference to a nearby transponder / satellite ... A: well, number of sources is the number of telephones, sources of traffic, connected to the network. ...
Link budget analysis and modulation technique	6/17/2008
Q: i read one of your previous answers related to link budget analysis but i could not get a few of the ... A: well, a modulator is a modulator, independent of what input you provide. so i guess the example used ...
Link budget analysis and modulation technique	6/15/2008
Q: i read one of your previous answers related to link budget analysis but i could not get a few of the ... A: saturation flux density is the power density required at the input of the satellite's antenna to ...
Satellite uplink power in C and Ku band	6/10/2008
Q: Could you please clear this thing that either C band or Ku band require higher uplink power to fire ... A: the key lies in the antenna gain, as explained in the previous answer. changes in frequency result ...
Satellite uplink power in C and Ku band	6/9/2008
Q: Could you please clear this thing that either C band or Ku band require higher uplink power to fire ... A: Typically, assuming all things equal: - same antenna diameter - same carrier characteristics C band ...
Regarding Satellite Footprints...	6/9/2008
Q: Could you please tell me about the footprints and their sizes that on which parameters they are ... A: from the satellite's point of view, there are mainly three types of coverage or footprint 1. the ...
Dish antenna	6/8/2008
Q: we are trying to receive the signals from a DSNG van for live feed the satellite details are as ... A: what you need to do is to perform the full link budget for the carrier you intend to transmit in ...
Link Analysis Calculation.	6/8/2008
Q: (1)How can we find satellite parameters ? For example NSS-6 (2)How can we find LINK parameters ? (3) ... A: this is a very complex subject and question. we could spend hours going over every element and the ...
SATELLITE DATA NETWORK	6/7/2008
Q: Sir I am working for an engineering solution provider in Pakistan. I have been given a task to ... A: OK, i suggest you do a google search on iridium data services and also one for globalstar data ...
SATELLITE DATA NETWORK	6/6/2008
Q: Sir I am working for an engineering solution provider in Pakistan. I have been given a task to ... A: well, 9.6Kbps is really nothing, so you have lots of options available the first one that comes to ...
Link budget	6/4/2008
Q: I want to know how to determine the HPA size from link budget result (the tool i'm using is LST5)? ... A: well, it all stems from the required total EIRP from the link budget. remember that during the link ...
Link budget	6/4/2008
Q: I want to know how to determine the HPA size from link budget result (the tool i'm using is LST5)? ... A: well, using LST5 you just need to go and select from them main menu the HPA button. and input the ...
satellite communication	6/2/2008
Q: why is uplink frequency kept larger than downlink? is it related to wavelength and directivity? A: there are various reasons why today the uplink frequency is larger than the downlink, but these ...
Upconverter	6/2/2008
Q: (1)What are the components are their in the upconverter which convert IF Signal( 70 MHz or 140 MHz ) ... A: I'll try to answer them in order this document might interest you ...
Beacon frequency( at downlink )	5/31/2008
Q: What is the Beacon frequency? (1).What is the Beacon level? (2).how to calculate the Beacon ... A: beacon carriers or frequencies are stable signals included in the frequency plan of a satellite to ...
waveguide	5/31/2008
Q: Sir, In most of the HUB Installations for teleports that I have installed , I have used either ... A: actually, in some antenna systems, the feed assembly has circular waveguide runs (in cassegrain or ...
antenna 9.4 (Andrew)	5/29/2008
Q: I WANT TO FIND THE ANTENNA GAIN OF THIS ANTENNA.I KNOW ONLY (1) DIAMETER OF THIS ANTENNA =9.4 MTR ... A: there is no simple answer to your question. the basic expression relating reflector gain to ...
Reg: Vsat link budgetting	5/28/2008
Q: what are the points need to be consider while budgeting the up an down link at the remote end? A: in any link budget you have to consider: 1. characteristics and location of the transmitting and ...
satellite beam	5/24/2008
Q: How is that Ku band has more focused beam? A: there is a fundamental property of any antenna radiation pattern. the wider the beam, the lower the ...
Nilesat101 coverage in Kigali-Rwanda-Africa	5/22/2008
Q: I am interested to capture Nilesat 101 at Kigali-2-30east-Rwanda in central africa. What could be ... A: this link has the information you need http://www.lyngsat-maps.com/maps/nile101.html in it you ...
Receive signal level	5/15/2008
Q: On a satellite modem, what is the relationship between Eb/No and RX signal level. I have noticed ... A: the Eb/No ratio at the receiving end is directly proportional to the C/N, the carrier to noise ...
gps	5/13/2008
Q: i was wondering why does a gps need a satellite to tell you where you are. why cant they just ... A: well, i do not think technology is an obstacle. the question is how much it will cost to put a ...
gps	5/13/2008
Q: i was wondering why does a gps need a satellite to tell you where you are. why cant they just ... A: the satellite positioning systems uses actually more than one satellite to determine your position. ...
Satelitte tronsponders .	5/6/2008
Q: 1.How many transponder are there in each satellites. 2.What are the maximum and minimum strength ... A: actually, the number of transponders varies from satellite to satellite. i believe a satellite ...
satellite communication	5/5/2008
Q: My question is that how can i calculate the downlink frequency if i have uplink frequency can you ... A: the relationship between uplink frequency and downlink frequency depends on the satellite's local ...
need to ask	5/5/2008
Q: I had taken a bachelor degree in electronics & communication engineer I studied satellite ... A: regarding your first question, maintenance, testing, operations, that is but one small part of all ...
Noise or TI Problem	5/4/2008
Q: Good day... Im using VSAT stabilized antenna(Seatel) and were having noise problem when our vessel ... A: This is an example http://www.twpinc.com/twpinc/control/category/~category_id=TWPCAT_11 the ...
satellite link	5/4/2008
Q: What has to be the receiver sensitivity or threshold (uV or dBm), for an acceptable TV link, with ... A: the minimum received value for a given received signal quality depends on the type of modulation ...
Intradermic GPS	5/3/2008
Q: I´m a physician from Venezuela and in my country we are confronting a situation that it is blocking ... A: i am afraid my main field of work is not hardware design, so i can not collaborate with you in the ...
VSAT design	4/28/2008
Q: I am trying to understand how to design a VSAT earth station. I want to know what are the equipments ... A: when you design a link, you use bandwidth and power from the transponder. A transponder is ...
Frequency conversion	4/23/2008
Q: I want to know that How RF frequency can be converted into IF frequency? What is the formula for the ... A: no. as i said, it all depends on the central frequency of the local oscillator you are using. For ...
signal degradation by rain	4/22/2008
Q: Which satellite band is less prone to signal degradation from rain...the Ka band or Ku band? I'm ... A: yes, that is correct. Rain becomes a problem after about 8 Ghz. Ku band is located in the 10.75 to ...
Frequency conversion	4/22/2008
Q: I want to know that How RF frequency can be converted into IF frequency? What is the formula for the ... A: it all depends on the frequency of the local oscillator of your downconverter or upconverter the ...
IBS overheads	4/21/2008
Q: When and why are IBS overheads used in SCPC circuits? A: sorry about the delay in answering IBS is the intelsat business data service. It is a set of ...
VSAT design	4/16/2008
Q: I am trying to understand how to design a VSAT earth station. I want to know what are the equipments ... A: the dehydrator is almost always used when you have a long waveguide run, so in the hub if you do not ...
link margin	4/14/2008
Q: what is link margin? is it different to Eb/no or c/no? what are the parameter reflect link margin ... A: In a nutshell, link margin is the amount of extra power that you have in the system to withstand ...
C/N,C/No	4/12/2008
Q: how to calculate the Carrier to noise ratio C/N and carrier to noise ratio density ie C/No. A: The C/N and C/No are functions of the transmitted power, frequency, system noise and separation ...
operating flux density	4/5/2008
Q: how to calculate the satellite operating flux density, while calculating the transmit EIRP.wahta re ... A: I will reuse part of a previous answer (discussing saturation fluz density and downlink EIRP), as i ...
Combiner & Splitter	4/2/2008
Q: Can you kindly explain to me the difference between combiner and splitter and how they are ... A: Basically a splitter and a combiner are two sides of the same coin: A splitter receives a signal and ...
VSAT design	4/2/2008
Q: I am trying to understand how to design a VSAT earth station. I want to know what are the equipments ... A: A vsat antenna has the following elements: transmit chain: vsat indoor unit transmit module ...
Antenna gain	4/1/2008
Q: I like to know how to calculate the antenna gain for both transmitting and receiving for a parabolic ... A: the reflector antenna gain depends on the effective capture area of the antenna (tied to the maximum ...
Signals conflicts	3/31/2008
Q: How can we be sure that, when a terrestrial system is transmitting a signal to a satellite, no other ... A: there are various levels of control imposed to a satellite network before it can start operations ...
satellite constellation	3/31/2008
Q: I wish to know about Walker Constellation and its design related issues. A: i think your best option to understand about non -geo constellations is the website of Dr. Lloyd ...
satellite communication	3/27/2008
Q: what is the difference between DVB-S and DVB-DSNG A: the differences between DVB-S and DVB-DSNG stem from the fact that DVB-S is a standard intended for ...
telecommunication	3/26/2008
Q: Question 1. What is the difference between Ku band and Ka band. Question 2. What is C band and ... A: Ku and Ka are the names given to two different frequency bands allocated for the Fixed Satellite ...
splitter for direct tv	3/20/2008
Q: Installer came out to apt and since there is only one line into apt it is impossible to watch one ... A: in order to do that (watch one channel while recording another) you need two receivers. Some ...
Ku Band coverage	3/19/2008
Q: Can you provide (or point me to) a global coverage map for all Ku band providers? Does Ku have full ... A: Ku band coverage is normally limited to regions within a continent or at most half a continent. ...
Communication payloads	3/14/2008
Q: Can you recommend a few good web sites which will explain how a satellite comm payload works. ... A: i think here http://info.ee.surrey.ac.uk/Teaching/Courses/eem.scma/ you will find everything you ...
VSAT	3/14/2008
Q: 1. Where the SFD(sat) of a satellite is applicable? Is it at EOC? 2.What is the correct way to ... A: no, those are fixed settings, and do not represent how your carrier will come in. Some transponders ...
satellite communication	3/7/2008
Q: 1.what is the difference between communication relay and communication satellite? 2.what are the ... A: a sidereal day is defined as the period of time required by the earth to rotate once, on its axis, ...
Terrestrial Interference in Ku Band	3/7/2008
Q: I was told tht since Ku Bnad is reserved for staellite communications, the possibility of ... A: this document is interesting: http://www.andrew.com/search/bn_TP-100319-EN.aspx Even though ...
AM FM modulations, tower height	3/6/2008
Q: I need to know that what is symbol rate in satellite communication? The reason why i ask this ... A: a modulation is a means of placing an information signal on top of another signal (called a carrier) ...
MPEC 4	3/5/2008
Q: what is the max no of channel we can uplink on 40 Mhz transponder in MPEC 4 using lower order of FEC ... A: well, it really depends on the quality of the encoder. if we follow this ...
2nd order harmonic	3/4/2008
Q: why do we check 2nd order, 3rd order harmonics A: harmonic is the name given to the fourier components of a signal. Harmonics are also undesirable ...
Symbol rate	2/27/2008
Q: I need to know that what is symbol rate in satellite communication? The reason why i ask this ... A: the bias t is inserted between an indoor device such as a modem or modem/coder or frequency ...
satellite communication	2/26/2008
Q: Why is the uplink frequency kept higher than the downlink? A: In satellite communications, the uplink frequency is of a higher value than the downlink mainly ...
Link Budjet	2/25/2008
Q: It is really nice to ask a question to you regarding satellite comm. I want to know what are the ... A: here are some tutorials i think will be helpful. ...
ku link	2/21/2008
Q: ku band is alot higher freq than c band, how far south america will it be viewable say trinidad W.I ... A: in the case of ku band, satellite coverage is normally tailored to a particualr region of interest. ...
Symbol rate	2/21/2008
Q: I need to know that what is symbol rate in satellite communication? The reason why i ask this ... A: the DVB-S standard includes a nice example for you to look at, if you want to see a block diagram of ...
C-Band	2/14/2008
Q: What is disadvantages of using C-Band in satellite communication? A: The main disadvantages of C band are that antenna sizes are large even for relatively small bit ...
I need answer plz	2/14/2008
Q: What are the the Advantages and Disadvantages of C-Band ? A: i would summarize it as this: Advantages: - large coverage from satellite antennas (hemispherical ...
Transponder & Modulation	2/12/2008
Q: I have heard that some satellite transponders can not support some modulations.For example Hellas ... A: In principle, a transponder is a transparent repeater, capable of supporting any modulation. ...
Dish Size	2/7/2008
Q: How do you calculate what size of Dish is required based on signal strength(dB). I used the formula ... A: The key element is the minimum received signal level for the specified operational threshold. In ...
Satellite phones	2/6/2008
Q: My name is Troy and i have a question regarding satellite phones. How reliable are they when it ... A: well, i am not a satellite phone user myself, but i am sure you can get encrypted communications ...
Range of Satellites	1/14/2008
Q: My question is: How much of the earth's surface can a satellite connect to? For example, if a ... A: antenna gain is not measured in percentage. For an example of global coverage, use as a reference ...
satellite link design	1/10/2008
Q: Respected s/m write about satellite link design as fast as possible, is satellite link insensitive ... A: here is a tutorial you will find useful. ...
SCPC	1/7/2008
Q: What is the Acquisition Range, Acquisition Offset & Reacquisition time regarding Vsat ... A: the terms carrier co-pol and cross-pol refer to the carrier to noise ratio observed in the ...
need to ask	1/3/2008
Q: can you recommend me some online resources to obtain some information about satellite encryption ... A: ok, so definitely what you need is general encryption. Look for a general encryption tutorial, ...
SCPC	1/3/2008
Q: What is the Acquisition Range, Acquisition Offset & Reacquisition time regarding Vsat ... A: Well, i will start with the definition of the terms and work towards an answer. Acquisition range is ...
need to ask	1/1/2008
Q: can you recommend me some online resources to obtain some information about satellite encryption ... A: actually the links i sent are what you are looking for. Look particularly at the white papers of the ...
need to ask	12/30/2007
Q: can you recommend me some online resources to obtain some information about satellite encryption ... A: i do not have specific links on the topic, i have not found a single site with all the answers. I ...
Satellite Transponder Bandwidth	12/26/2007
Q: I am wondering about the relationship of occupied satellite bandwidth in relation to symbol rate or ... A: bandwidth is calculated as follows: BW = (Info rate)(coding expansion factor)(modulation ...
link budget	12/25/2007
Q: what is SFD, I/o back off, o/p back off ? how they can be calculated? what are their importance in ... A: com. let's start with SFD: After transmission, the wave fronts spread spherically and the amount of ...
data encoding	12/11/2007
Q: How does encoding affect the speed of data transmission . Any links for furthere reference will be ... A: well the short answer is that it doesn't. Effectively, if you encode 128Kbps stream and decode it, ...
GMSK and FSK	12/11/2007
Q: Before you answered that GMSK is better for a student satellite. But i had read that GMSK require ... A: you can verify the difference in power required under theoretical conditions on the links i provided ...
Encoding bitpattern	12/10/2007
Q: How do I encode the bit pattern 01100 using ASK , BFSK , BPSK . Any help would be highly appreciated ... A: actually, the complex to real gives a worked out example. you can always google BPSK modulation ...
Encoding bitpattern	12/9/2007
Q: How do I encode the bit pattern 01100 using ASK , BFSK , BPSK . Any help would be highly appreciated ... A: it is a bit difficult to explain in words alone. But these links provide some aid: ...
Bandwidth vs. Symbol Rate in a PSK modulated signal	12/6/2007
Q: Everyone keeps telling me that Bandwidth is equal to Symbol Rate in a PSK modulated signal (or that ... A: a modulation scheme is in essence a frequency translation combined with another mechanisms that is ...
satallite signal strenth	12/4/2007
Q: We currently have a customer who has the main dish about 300 ft away from the hdmi television we are ... A: well there are two options. you can install a line amplifier, which will augment the signal level ...
Satellite Transmission Power	12/3/2007
Q: If I want to lease bandwidth from a Satellite operator, am I right to say that they normally have a ... A: well, the actual power limit depends on the diameter of the antenna you are planning to use. In ...
i want more channels	12/1/2007
Q: i am from Pakistan. Sir i want to ask that how i get mnet channels free in my country with out ... A: ok, sorry my previous answer wasn't helpful First, you need to buy a satellite dish (Ku or C band, ...
how to fix the power constraints	12/1/2007
Q: well u did solve my problem the last time which was regarding the antenna to use. but now i havethis ... A: i think you should perform the link budget and decide based on that the best combination of antenna ...
Antenas offset RX y TX	11/21/2007
Q: Hola, sin contar la parte electrónica cual es la diferencia si la hay entre una antena offset RX y ... A: Hol Peter, gracias por la pregunta. La principal diferencia que existe entre una antena RX only y ...
Downlink vs uplink frequency in satellite communication	11/16/2007
Q: Why the downlink frequency (from satellite to the earth base station) is higher than the uplink ... A: In satellite communications, the uplink frequency is of a higher value than the downlink mainly ...
ebooks!	11/15/2007
Q: I would like to point me to a site or send me ebooks that you have about satellite communications.I ... A: tanks for the question. unfortunately, i can not send you ebooks on the subject. However, there are ...
Satellite	11/15/2007
Q: As the frequency increases more atmospheric attenuation. So it require more power for uplink ... A: Yes, the higher the frequency the higher the atmospheric losses. You would need an equivalent ...
satellite signal lost	11/13/2007
Q: We had a satellite with 2 receivers installed about a month ago. It's working just fine during the ... A: well, from what you say it seems that you have extra losses in your receive path. What could be ...
Satellite Data Streams	11/12/2007
Q: I would like to ask you a short question (maybe very basic for your knowledge but I find it ... A: ok, so you refer to case 1. the user packets. the link i wrote on the surrey course is very good ...
adjacent satellite interference - opposite polorization	11/2/2007
Q: Mr Emiliani, I am working on a Bit Error Rate simulation to show the impact of adjacent satellite ... A: To conduct a simulation of the problem of cross-polarization interference, you need to consider ...
modem and tnc	11/2/2007
Q: which is the best software available (keeping in mind price constraints) that will automatically ... A: well, i am not an active amateur satellite communications user, so i can not really comment on the ...
GAUSSIAN SHIFT MODULATION KEYING	11/1/2007
Q: COULD U PLZ EXPLAIN HOW DOES THIS WORK? ALSO WHAT IS THE BEST MODULATION TECHNIQUE TO BE USED IN A ... A: you are very welcome. if you have to work on the VHF range then a single monopole will not be as ...
GAUSSIAN SHIFT MODULATION KEYING	11/1/2007
Q: COULD U PLZ EXPLAIN HOW DOES THIS WORK? ALSO WHAT IS THE BEST MODULATION TECHNIQUE TO BE USED IN A ... A: Are you referring to the cubesat project? let's go step by step. A constant envelope modulation is ...
GAUSSIAN SHIFT MODULATION KEYING	10/31/2007
Q: COULD U PLZ EXPLAIN HOW DOES THIS WORK? ALSO WHAT IS THE BEST MODULATION TECHNIQUE TO BE USED IN A ... A: GMSK, standing for Gaussian Minimum Shift Keying, is a digital modulation method similar in its ...
Satellite communication Engineering Technology	10/27/2007
Q: I am a transmission engineer working for a telecommunication company in Africa. I am used to ... A: The whole concept is to provide a transport medium for the Abis protocol connecting a BTS with BTSC, ...
cant get freeview	10/21/2007
Q: have jst purchased a openbox f-300fta digital satellite receiver and cant seem to get any freeview ... A: I am not an expert on satellite tv, so i suggest some actions but i also suggest you repost this ...
Astra 2 installation in the Netherlands	10/10/2007
Q: we have just installed a 70cm(ish) dish on the roof to pick up Astra 2 free-to-air from the UK. I ... A: Well, in principle if you have your dish correctly pointed, you can see all channels broadcasted ...
KU Band	10/6/2007
Q: How to Calculate the frequency and Bandwidth for KU band ANSWER: Hi, thanks for the question. I ... A: cool. >>I need 3 carriers of 2 MHz. what is the symbol rate and centre frequency for all 3 carrier ...
KU Band	10/2/2007
Q: How to Calculate the frequency and Bandwidth for KU band A: I would like to understand more about what you want to do The Ku band is a range of frequencies ...
satellite	9/30/2007
Q: why we need satellite for comunication? what is the advantages and disadvantages of satellite in ... A: i would like to thank you for your ratings and ask you, if i may, the reason why you considered my ...
tecommunication	9/29/2007
Q: advantages and disadvantages of sattelite communucation A: well, satellite communications are ideally suited for establishing one way links (broadcast) or ...
satillite communication	9/7/2007
Q: what will happen if we make uplink freq smaller than downlink freq A: In satellite communications, the uplink frequency (earth to satellite) is of a higher value than the ...
satellite Bandwidth optimization	9/5/2007
Q: I am doing my project work on Optimizing Satellite bandwidth in communication. Please kindly help me ... A: This is a very broad subject. Could you be a bit more specific? Are you looking at optimizing the ...
Satellite Internet in India	8/31/2007
Q: I am in need of 1-way high speed satellite internet in India. I have 29kbps cellular phone which can ... A: first, one thing i noticed is that your are confusing the data rate with the amount you are ...
Satellite Internet in India	8/31/2007
Q: I am in need of 1-way high speed satellite internet in India. I have 29kbps cellular phone which can ... A: let me see if i understood correctly. you have a data link from your mobile phone that you want to ...
Satellite signal amplifier	8/14/2007
Q: I am living overseas in a high-rise apartment. I receive satellite programming via AFN (Armed Forces ... A: What you need to improve your reception is a change in the antenna's G/T or figure of merit. this ...
Data rate required	8/2/2007
Q: DAer sir : I want to install a SCPClink between two sites to transfer data ( large video Files ) . ... A: Before answering this question is is necessary to have more information such as: what satellite do ...

All Questions in This Category

Email this page