| Subject | Date Asked | Expert |
|
| Eb/No | 7/18/2008 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 ...
|
| Anteena | 6/7/2008 | Mark Posen |
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 ...
|
| SATELLITE DATA NETWORK | 6/7/2008 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 | Luis Emiliani |
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 ...
|
| Regarding Satellite Footprints... | 6/3/2008 | Nagy George |
Q: My question is regarding the satellite footprints that how they are decide and how they are limited. ...
A: Engineers tailor the footprint to suit the owner's maps (owners of satellites like Optus-Singtel, ...
|
| Question | 6/3/2008 | Mark Posen |
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 ...
|
| satellite communication | 6/2/2008 | Luis Emiliani |
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 | Luis Emiliani |
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 ...
|
| Bandwidth | 6/1/2008 | Mark Posen |
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, ...
|
| Beacon frequency( at downlink ) | 5/31/2008 | Luis Emiliani |
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 | Luis Emiliani |
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 ...
|
| Amplifiers | 5/31/2008 | Mark Posen |
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 ...
|
| antenna 9.4 (Andrew) | 5/29/2008 | Luis Emiliani |
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 ...
|
| vsat | 5/28/2008 | Mark Posen |
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 ...
|
| Reg: Vsat link budgetting | 5/28/2008 | Luis Emiliani |
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 ...
|
| data rate and SSPA size | 5/27/2008 | Mark Posen |
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 ...
|
| Internet access. | 5/24/2008 | Mark Posen |
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 ...
|
| satellite beam | 5/24/2008 | Luis Emiliani |
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 ...
|
