From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id EDE7F3CB37 for ; Sat, 2 Mar 2024 10:18:27 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1709392705; x=1709997505; i=moeller0@gmx.de; bh=QHJcJ5tFIRZqMXxn6670R50gFH+HNgzjfwQCzE3/dDA=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References: To; b=n44ISKaq4jurHLDMejfPro8nfZexJYnzRFxlgcAF0tNkStfhIE0fdvE2W1UzS5T8 3xeFLQZ2XLyR/yl7NKRT0nGb3hWj1fv02K42ZUMkCjP4WRxDj9o66gutzTHb90P9k nRNqtFBB2yB9Px/6VfxocqEIKf4ttEF+6nMUhGtUEVT0/dKgV1Q3iMKfe+dWTwece ePDAwio4isOaKlEuWM6cbS/9VQ84NI2kgHsY4hjSrFgJeWNgHxIUVZ2bNiMBtj+ms fY3Bo3E5wxReAgMAcSjmMsIaeA0qldAhKLioeqVZ8Kh3zuBeurZnf2L04mDOQ3jtF 7VoCNE3MiMZ6+Ye7FQ== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from smtpclient.apple ([77.3.124.127]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1M1Hdq-1ri5pD2ZEg-002lcn; Sat, 02 Mar 2024 16:18:25 +0100 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3774.400.31\)) From: Sebastian Moeller In-Reply-To: Date: Sat, 2 Mar 2024 16:18:14 +0100 Cc: Dave Taht via Starlink Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Hesham ElBakoury X-Mailer: Apple Mail (2.3774.400.31) X-Provags-ID: V03:K1:02MWVZZPbUjy8t29s6zazQITSzU+q5v64QC0HVsL+wjTYzVkPmQ WX0JX3w+wKHghthJ1ckNOyvrIxNzAJ2Urt/7JRGxzLxkq1zs8WeCPv7l/APmiOWqTHxwkRz EHLVBY1WKsDF6fJ8BPj7iDCQJ5qxMuwNu/Bvxtakjoed1QmaGGIJnxt1NGE0gmefh7HMtlj 5XzR5JY0QdoAifWI9+ZkQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:8xUqgaWrnyk=;d5isC4OAKyP6IgcWl79TPqxcBTO NvrRzLHYDI7T6SXgu5lAeQHVbbBUaQBsBJzhaG4aeoWp++elpJQdSeNq/bAO4MTnmXzUFaXhl 6v19MeRVJ3m+/TE0l6Ijrp/sW2Z+HS6oEQ2o7S2hfGrlpoma7wc9SBR8GEXnjsZGRu5Ep64jp nX5JHZb7ek3ErVIAtIAekXEU1ieLP0XQs5KvRBUJXFFY8/r9idFka0P8FAb5mUxGvAvvQ7UQr EYnbJbCXC6ZQeqz+og5hbzp+Dv9BUmUADVOgF8Q22ONOLXyhZD8jlWD6fridLypKckP24oFuS ck0gtkDmEzB8bg/6Q78uz+0ewHdmWa/gsJr19Fd5fCaQr+CwfkIzinL2QHeTGKgt2uyhiwTOK 4D06FKXriSMX3ygJK1bvtyP+jwNNZjbqmsTixk8l2Y6i7GO4cKvx61W5F2nBpiSHPLKn29TqF bsw+qcWblLpqi8bXJHk3puVjOBE1VHOH99+yJHxGiMyvTp/YCalVQSnbvuKtIaMTPfSt3iLwy 4vXFx2JXdT4kGbQPEMHr6P0E5o67LvNPVI5XKstmBoRQG2X99CBE51Gm54w1LgjzC2MV8rO/1 1mDMNyYGFLGfe5o0f+PHe894qc6Op1oNidaIWj+jQbMWxvethm51qeTGfdG70V4h3CWyRvnw/ 9rrJiYwFFKjhg0CcmraBtdgedLosUTPufE064X3bTMJZNH98UzTJz5ctFtukBkieW5MsIIyP4 ybA6Bd+NGkJs9bPU5zAFWwQ9LWppwu1RWRIE/OQk0vbg2no1LOV8IPNx2w9Y0wvwSaRReAn1+ 7HH7SvLd8Y08iv5f031RHMM95cejGrZ9GMPL0FyEVI7Pg= Subject: Re: [Starlink] Time Synchronization in Satellite Networks X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Mar 2024 15:18:28 -0000 Hi Hesham > On 2. Mar 2024, at 16:03, Hesham ElBakoury via Starlink = wrote: >=20 > Time synchronization, for satellite networks, faces several = challenges: > 1. Signal Propagation Delays: Unlike terrestrial networks where = signals travel through cables at the speed of light, [SM] The speed of light in your typical glas fibers (and accidentally = the information propagation speed in metallic conductors) comes in = roughly at 2/3 of the speed of light in vacuum, while the speed of light = in air at see level is a mere 90 KM/s slower than in vacuum.=20 > satellite communication involves signals traveling vast distances = through space. This creates significant delays. [SM] Sure distances might be larger, but propagation speed is around = 100000Km/s faster... my main point is speed of light is a) dependent on = the medium b) not the things that differentiates space from the earth's = surface here, but mere geometry and larger distances on larger = spheres... > 2. Clock Drift: Even highly precise atomic clocks, used in satellites, = are susceptible to "drift" - gradually losing or gaining time. This = drift, caused by factors like temperature variations, radiation = exposure, and power fluctuations, can lead to inconsistencies in = timekeeping across the network. > 3. Signal Degradation: As signals travel through space, they can = degrade due to factors like atmospheric interference, ionospheric = disturbances, and solar activity. This degradation can introduce noise = and errors, impacting the accuracy of time synchronization messages.=20 > 4. Limited Resources: Satellites have limited power and processing = capabilities. Implementing complex synchronization protocols can be = resource-intensive, requiring careful optimization to minimize their = impact on other functionalities. > 5. Evolving Technologies: As satellite technologies and applications = continue to evolve, new challenges related to synchronization might = emerge. For example, the integration of constellations with thousands of = satellites poses unique synchronization challenges due to the sheer = scale and complexity of the network. > These challenges necessitate the development of robust and efficient = time synchronization protocols for satellite networks and an integrated = satellite and terrestrial networks > Are you aware of such time synchronization protocols? > I would think that using Satellite simulators is the most viable way = to develop and test these protocols given that using satellites is not = that easy. > Thanks > Hesham >=20 >=20 >=20 > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink