Former satellite telecom engineer here, have built high capacity two way C, Ku, X and Ka band earth stations. Two big problems with China:
1. Smuggle rooftop CPE into country? Manufacture domestically in grey market factories?
2. Very low cost for Chinese law enforcement, in Xinjiang, to buy and use portable spectrum analyzers to locate the Tx frequencies coming from a 30cm-50cm sized rooftop phase array antenna, aimed at the sky. To be a viable satellite broadband product it has to have a fairly strong Tx (in EIRP). No matter what band it is in from 10.5 up to 70GHz.
1) The problem with using an ISM band for earth to space is precisely because it's exceptionally noisy. You want the best possible SNR for two way satellite, either direction. With a small satellite that orbits relatively close (LEO to low MEO, compared to geostationary), which will likely have a system architecture composed of numerous focused spot beams... If you were to design a series of spot beam on the satellite body with ISM band antennas aimed at major cities all you would achieve is gathering noise.
2) Not going to help much unless the upstream is so little that's basically useless. The same antenna is used for both Rx and Tx so you still need significant gain to overcome the path loss and have sufficient link budget for the space-to-earth traffic.
With current geostationary-based technology any significant VSAT is easy to spot: If you want to use higher-order modulations and coding, you need gain. Which means you need at least a 1.8 to 2.4m size antenna for a serious earth station. Possibly you're confusing a small VSAT with the Rx-only TVRO type dishes which are everywhere?
Yes, they are easy to spot, and they are being spotted and their owners being jailed/executed/gutted for organs. This does not mean than an enormous amount of wealthy Chinese see their own private internet channel as a status symbol, and manufacturing of creatively styled antenna enclosures being a mid-sized industry here.
1. Smuggle rooftop CPE into country? Manufacture domestically in grey market factories?
2. Very low cost for Chinese law enforcement, in Xinjiang, to buy and use portable spectrum analyzers to locate the Tx frequencies coming from a 30cm-50cm sized rooftop phase array antenna, aimed at the sky. To be a viable satellite broadband product it has to have a fairly strong Tx (in EIRP). No matter what band it is in from 10.5 up to 70GHz.