SatSig topic:

Comtech Heights or iDirect VSAT network management systems and OpenAMIP

(Read 3199 times)

Nov 27^th, 2020 at 6:33pm

Hello All,

Which system is best iDirect or Heights(Comtech)

Can anybody explain?

Thks. Roll Eyes

Dec 1^st, 2020 at 10:58am

All I can suggest is that you study both with relevence to your particular requirements.

My experience suggests that the expertise and training of the staff is the most important factor in whether or not a service works well for the customer.

Dec 1^st, 2020 at 3:07pm

Thanks,
I know the TDMA based system is good for bandwidth sharing but creates high latency, big overhead and no video on sharing channel.
But cheaper due to share band on Upstream and cheaper remote modem,
Assume that extra power require for tdma burst rather then scpc.
My regards,

Dec 2^nd, 2020 at 1:27pm

Both iDirect and Comtech have undergone much development over the years and disadvantages of each of both TDMA and SCPC have been addressed.

TDMA can carry video, by transmitting the stream of data packets in longer bursts. A TDMA frequency plan now involves many return link freqencies and a particular return link frequency may be assigned dynamically to a very active remote site.

The difference between SCPC and TDMA has become blurred as it is now possible to set up SCPC just for the period of a phone call. The power needed to transmit TDMA or SCPC is the same at a remote site and depends on the bit rate.

Outlink carriers, hub to remote, are called TDM (Time Division Multiplex), and come in bit rates up to hundreds of Mbit/s and are continuous transmissions while containing a frame structure comprising blocks and packets of data intended for different recipients. It is even possible for different blocks to be of different modulation and coding to suit the recipient dish size or to dynamically deal with temporary rain fades at the remote receive site.

Comtech have developed an interference cancellation technique called "Carrier-in-Carrier". This allows two carriers to the tranmitted on top of one another. If you want a bothway service within the same satellite beam coverage this can halve your satellite transponder costs.

Consider if you really need an expensive network management system. Both iDirect and Comtech equipments work fine on their own in simple systems. If you plan a larger network, and you need to choose between iDirect and Comtech network management systems I suggest you talk in detail to both companies, explaining exactly what you want to do. Ask also about encryption and security and don't forget training costs for the staff, both initial and ongoing.

Dec 3^rd, 2020 at 6:19pm

Here is some good information about both SCPC and TDMA, relating to the SpaceBridge (was Advantech Wireless) ASAT VSAT network hub and the ASAT C7700 remote user terminal.

Looks like a good competitor to iDirect, ViaSat and Hughes.

Read here:

https://www.spacebridge.com/wp-content/uploads/WaveSwitch_Whitepaper.pdf

Dec 3^rd, 2020 at 8:41pm

Thanks a lot for explanation and info,
Just didn't find any info about the mobility on SpaceBridge system,
Does they provide the comms at sea?
Comtech and Idx are providing with mobility like OpenAMIp etc.
My regards.

Dec 4^th, 2020 at 9:09am

The C7700 is suited to the home/office user.

Spacebridge do a professional U7400 modem/router with OpenAMIP for mobile/maritime applications. This modem/router comes in rack mount (U7400) and outdoor formats for both civil (WU7400) and military (MU7400) applications.
See: https://www.spacebridge.com/product/u7400-2-2/
Datasheet: https://www.spacebridge.com/wp-content/uploads/2019/02/PB-U7400-DS-008-19038.pdf

Contact Spacebridge and discuss your particular requirements.

Dec 7^th, 2020 at 2:46pm

Thanks a lot man.
Really appreciate you,