From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sainfoin-smtp-out.extra.cea.fr (sainfoin-smtp-out.extra.cea.fr [132.167.192.228]) (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 1F3743CB37 for ; Sat, 2 Mar 2024 12:09:29 -0500 (EST) Received: from pisaure.intra.cea.fr (pisaure.intra.cea.fr [132.166.88.21]) by sainfoin-sys.extra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 422H9TCp003588 for ; Sat, 2 Mar 2024 18:09:29 +0100 Received: from pisaure.intra.cea.fr (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 1DBB220D8FF for ; Sat, 2 Mar 2024 18:09:29 +0100 (CET) Received: from muguet1-smtp-out.intra.cea.fr (muguet1-smtp-out.intra.cea.fr [132.166.192.12]) by pisaure.intra.cea.fr (Postfix) with ESMTP id 148CC20D8FB for ; Sat, 2 Mar 2024 18:09:29 +0100 (CET) Received: from [10.11.240.6] ([10.11.240.6]) by muguet1-sys.intra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 422H8rJP044880 for ; Sat, 2 Mar 2024 18:09:28 +0100 Message-ID: <32dfaf13-9e04-4148-8ff9-3d5fda8b9dd0@gmail.com> Date: Sat, 2 Mar 2024 18:09:28 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr To: starlink@lists.bufferbloat.net References: From: Alexandre Petrescu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CEA-Virus: SOPHOS_SAVI_ERROR_OLD_VIRUS_DATA 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 17:09:30 -0000 Le 02/03/2024 à 16:03, Hesham ElBakoury via Starlink a écrit : > 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, satellite > communication involves signals traveling vast distances through space. > This creates significant delays. > > 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. > But, in a probably surprising way, it is GPS satellites at MEO altitudes with their higher-than-LEO latencies that calculate and provide accurate time on Earth. Alex > 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. > > 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 > > > > > > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink