Thursday, February 24, 2022

SpaceX is testing Starlink roaming

A failed roaming test
Last April, Elon Musk tweeted that Starlink "should be fully mobile later this year, so you can move it anywhere or use it on an RV or truck in motion." It is good to know that mobility with a standard dish is in the works, but it's not yet available.
David Lang had been able to connect his Starlink terminal about fifteen miles from his home in Simi Valley, California, but when he brought it to my place in Carpinteria California, about forty-three miles away and in a different coverage cell, it failed to connect.

David's experience is not unique -- others have reported similar inconsistency on social media, but if one is willing to change the registered address of their terminal, it can be moved -- if there is available capacity at the new location.

Consider the experience of Marcus and Julie Tuck, who have been digital nomads for eight years and Starlink users since April 2021. As of December 16, 2021, they had registered at one hundred different addresses and had service at 157 locations. 

The Tucks and their truck
They experienced a significant roaming change while driving in central California. On February 11, 2022, they noticed they could move into a new cell and retain Starlink service without registering an address change. Later, when they crossed from California to Nevada, they had to enter a new address, but when they returned to California, they did not have to change it back. They have not changed it subsequently but will have to when they enter Mexico.

When David Lang brought his terminal to my home, he would have risked losing the ability to connect when he returned home if he had temporarily registered his terminal at my address. When the Tuck's experience becomes available, users will be able to leave home for a trip and return without risking the ability to reconnect at home.

David's visit was a week after the Tuck's experience, so roaming has not yet been rolled out. Perhaps the Tucks were in a limited test area or were selected by SpaceX because of their frequent address changes.

The Tucks had fixed roaming, not the in-motion connectivity Elon Musk promised, but it is a first step and there are still unanswered questions about roaming like:

  • Will terrestrial roaming while in motion require a different terminal? (It will at least have to be mounted differently). Planes, ships, and military vehicles will surely use different terminals. 
  • Since capacity must be reserved for roaming, the service will cost SpaceX. Will they charge for roaming and, if so, how -- by the month, the cell transition, the ground-station transition?
  • Will the roaming fee be less in low-demand, unsaturated areas? 
  • Will it be different for transitions into or out of high-demand areas? A function of the number of open slots at the time of transition?
  • Because of capacity limitations, they will not be able to guarantee 100% roaming success. Might we see a collective service-level guarantee like "99% success globally each month"?
  • How long will it be before a Starlink terminal is offered as an option on Tesla cars and trucks? 
  • How long will it be before a Geely Holding Group terminal is offered as an option on Volvo, Mercedes and other Geely brand autos?
  • SpaceX has begun launching satellites with inter-satellite laser links and the other LEO broadband operators will follow -- how will that affect roaming?
  • Eventually, I expect we will have optical links to ground stations with climate and weather-aware routing -- how would that affect roaming?
Elon missed his target date, but he seems confident that we will eventually have "full mobility" -- let's hope he is right.

Update 2/25/2022

This map shows the Tuck's most recent travels. Note that they did not have to re-register during the stops marked with green push points. They re-registered after crossing the state line into Nevada but did not re-register after returning to California.

Star = registered address

A. First of five locations after registering
B. First of seven locations after re-registering
C. First of fourteen locations after crossing the state line and re-registering
D. Fourteenth location after registering, 2/23/2022

Update 3/3/2022

SpaceX has enabled fixed and mobile roaming in Ukraine and reduced peak power consumption.

Update 3/12/2022

The Tucks mounted the Starlink dish horizontally on the top of their RV and used it while in motion. They have reported on a 101-mile drive at an average speed of 45 miles per hour and a top speed of 54. During the test, they live-streamed a video, and Marcus' wife listened to a live UK radio broadcast while doing a range of general Internet surfing, social media, etc. Below is a snapshot from a video log of the entire trip, speeded up to run in 2 minutes.

Update 3/13/2022

When the Tucks crossed into Mexico, they feared roaming would fail, but roaming and in-motion connectivity continued working.

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