The slingbox tuner is a discontinued product and was only capable of analog signal reception via it's integrated tuner.
The unit that you want is the slingbox pro hd unit which incoporates a hybrid analog and digital ATSC/QAM tuner.
The slingbox itself is what streams to your network as well as to the internet for in network and remote internet viewing. there is no computer used to "upstream the content".
As far as picture quality/resolution goes, the 600kbps and/or 3mbps HD requirements are recommended for stable viewing quality. Your particular upload stats are determined by the package you subscribe to from your ISP (internet service provider). You can run a speedtest at speedtest.net to find your specific speed stats. The "upload" speed at the slingbox hosting location is what prodominatly determines your picture quality during remote viewing sessions.
"The slingbox itself is what streams to your network as well as to the internet for in network and remote internet viewing. there is no computer used to
"upstream the content"."
Does it mean that I cannot use my PC and my software, as Microsoft Expression Encoder 4 Pro, to make it available for the Internet clients?
I know that using Microsoft Expression Encoder 4 Pro more than one client can connect at the same time, but in case I use www.slingbox.com/getstarted only one client can access it at the same time.
Also, I know that PC TV cards can be used by Microsoft Expression Encoder 4 Pro to stream it on the Internet.
No, you can not use microsoft video encoder to upload the content frokm the slingbox for multiple internet client viewing. the slingbox is a proprietary format and doesn't play nicely for that purose by their design. The decision for that is based on movie, studio and channel rights for that reason specifically only one stream can be accessed at any particular time from the slingbox (either in-network or remotely) at any given time.
Both the slingbox and hava's paceshifting devices are designed in the manner I designated above for copyright reasons.
What your trying to do is specifically against the terms of service of the product itself.