TEK NET
The Henderson Amateur Radio Club is pleased to present our Tek Net every Sunday evening, starting at 8pm local time (0300 UTC).
The audio portion of the Tek Net will be found on the Henderson Amateur Radio Club Repeater Network (RF). The audio may also be accessed via Echolink (W7HEN-R node 740644) and Allstar (node 44045).
The audio will refer to this page, so that the listener can more fully understand the concepts as they are presented.
All are welcome!
May 14, 2023
‘Whats right around the corner for your handheld cellular device?’
With the ever increasinmg amount of apps available for your cell phone, it seems to be only limited by an engineer or app designer’s imagination as to what capabilities and tools they can stuff in your cellular handset.
But what about the service to make these devices shine?
Tonight we are going to look at the latest in successful tests that could affect each and every one of us.
Earlier last week, a ground breaking 2G phone call between Texas and Japan was made.
AST SpaceMobile claims this is “the first time anyone has ever achieved a direct voice connection from space to an everyday cellular device”.
This will eventually set the stage for a Globally accessible space-based cellular network.
Seen to the right is the latest AST SpaceMobile’s BlueWalker 3 (BW3) satellite that is in a LEO (Low Earth Orbit) position at this time.
BlueWalker 3 was launched from Cape Canaveral in August 2022 atop a Space X Falcon 9.
BW3’s solar panels are on the back of the antenna arrays.
The phone call was made from an un-modified Samsung S22 in Midland, Texas, using real mobile spectrum from AT&T and connected to an iPhone used by Japanese tech giant Rakuten in Japan.
This was definitely a “LOOK MA,…NO CELL TOWERS moment!
There was several other companies working on this experiment.
Besides the engineers at AT&T, Rakuten the UK-base telecommunications company Vodafone assisted with the test.
Ordinarily, our everyday smartphone shouldn’t be able to communicate directly with satellites in space because they operate on different frequencies and requiring local cell towers.
The way that AST SpaceMobile got around this was by purposely designing it’s network architecture to mirror the 3GPP (3rd Generation Partnership Project that cellular towers service is based on).
In the FCC filing AT&T is leasing certain 850Mhz cellular A and B blocks of spectrum as well as some 700Mhz B and C block spectrum to AST SpaceMobile, which they can only use where AT&T doesn’t have coverage on those frequencies.
If a cellphone doesn’t see any signals from a local tower, it will attempt to connect to the BW3 thinking its local service.
This isn’t your standard satellite!
This monster measures in at 693 square feet and is the largest commercial communications array ever deployed in to Low Earth Orbit. (almost 64 square meters.)
Capable of routing standard cellphone signals from over 1,000 miles away.
This is accomplished thanks to it’s 658 antenna elements per panel array totaling 100,000 individual antenna elements.
That’s one heck of a “Foot print”.
