Starlink 想要在太空直接提供 5G 網路訊號讓地面手機使用

Hacker News 上看到 Starlink 打算跟 T-Mobile 合作,直接用衛星提供 5G 訊號讓地面手機使用:「SpaceX, T-Mobile to connect satellites to cellphones in remote areas (」,原報導在 WSJ 的「SpaceX, T-Mobile to Connect Satellites to Cellphones in Remote Areas」這邊,另外因為 paywall 的關係,可以在這邊讀。


Mr. Musk said the service would use second-generation Starlink satellites that would be outfitted with large antennas that cover swaths of land that have no service. SpaceX has a pending application before the FCC to launch around 30,000 of the second-generation satellites over time.

在另外一篇報導「SpaceX and T-Mobile team up to use Starlink satellites to ‘end mobile dead zones’」裡面有提到更細一點,不是衛星電話,是目前一般的手機:

The service won’t require mobile users to get a new phone. Musk said in or after a natural disaster, even if all the cell towers are taken out, the planned service should work.

不過可以預期只會有很基本的服務 (大概確保通話與簡訊會通),針對緊急危難狀況會特別有幫助:

Mr. Musk said that the bandwidth would be limited and that the new satellite service wouldn’t supplant existing ground-based cellular services. “This is meant to provide basic coverage to areas that are completely dead,” he said.

翻了翻 wiki,目前 Starlink 第一代衛星的軌道高度是 340km 左右,好像還不確定二代衛星會在哪個高度...

Hacker News 上有蠻多人在算技術上的可行性,除了訊號強度外,衛星與地面相對速度比目前地面上的交通工具都快,都卜勒效應 (Doppler effect) 看起來也是個會影響很多的主題...

不過討論裡面有提到 2021 年就已經有其他商用公司在幹類似的事情,所以看起來不只是講講而已?應該是有些可能性:「Lynk demos global satellite connection for ordinary phones and prepares for commercial launch」。

SpaceX Starlink 的延遲與速度

SpaceXStarlink 已經有些人開始在測試了,在 上也已經有人挖到資料,可以看出他的延遲與速度了:「SpaceX Starlink speeds revealed as beta users get downloads of 11 to 60Mbps」。

報導的資料主要是從 Reddit 上的拉出來的,如果要看原始的資料,可以參考「List of Confirmed Starlink Speed Tests」這篇列出來的連結。

延遲可以低到 20ms 左右,不過比較常見是 30ms~40ms,高的時候可以看到 90ms 左右,這樣看起來頗有競爭性的,下載速度看起來也還不錯...

目前看起來都是加州地區的測試,查了資料看起來是目前開放的區域有限 (加拿大南部與美國北部),之後可以看開放其他地區的情況。

另外未來如果更多衛星打上去,網路的品質應該會更好,不過對天文學家看起來是場災難,光害的問題看起來很嚴重,像這張曝兩秒的照片就可以看出來這六顆的情況:(出自「File:Starlink 6 satellites.jpg」)

SpaceX 得到 FCC 的同意架設家用的衛星網路

在「FCC approves SpaceX’s plans to fly internet-beaming satellites in a lower orbit」這邊看到的:

The Federal Communications Commission has approved SpaceX’s request to fly a large swath of its future internet-beaming satellites at a lower orbit than originally planned.


Under SpaceX’s original agreement with the commission, the company had permission to launch 4,425 Starlink satellites into orbits that ranged between 1,110 to 1,325 kilometers up. But then SpaceX decided it wanted to fly 1,584 of those satellites in different orbits, thanks to what it had learned from its first two test satellites, TinTin A and B. Instead of flying them at 1,150 kilometers, the company now wants to fly them much lower at 550 kilometers.

不知道價位會落在那個區塊... 如果價位夠低的話,也許是可以考慮當作偏鄉地區的通訊方案?至少是個備用方式...