Paper Details
| Authors | Zeqi Lai, Qian Wu, Hewu Li, Mingyang Lv, Jianping Wu |
| Conference | 2021 IEEE 29th International Conference on Network Protocols (ICNP) |
| doi | 10.1109/ICNP52444.2021.9651919 |
Abstract
Satellite-based Earth Observation (EO) systems are gaining popularity and widely used in many time-sensitive scenarios, including disaster monitoring, emergency response, forecasting and defense. Existing efforts for gathering EO data mainly rely on either ground station networks or geostationary (GEO) satellites. However, our quantitative analysis reveals that existing approaches are either limited as their achievable latency is far away from the desired value due to the insufficient coverage of ground stations, or hard to scale as the number of sensing satellites increases because of the high cost of GEO satellite relays.This paper explores the feasibility and performance of a novel approach that leverages emerging low Earth orbit (LEO) constellations to enable low-latency and scalable EO data delivery from space. We present OrbitCast, a hybrid EO data delivery architecture upon LEO constellations and geo-distributed ground stations to forward EO data from the source remote sensing satellite to a collection of end users. To handle the network dynamicity caused by LEO satellite movements and achieve stable communication over the satellite network, we propose a geo-location driven scheme to forward and deliver data packets. To demonstrate the effectiveness of OrbitCast, we build a testbed driven by public constellation information and implement the OrbitCast prototype on top of the testbed. Extensive realistic-data-driven simulations demonstrate that OrbitCast can significantly reduce the latency as compared to other state-of-the-art approaches, and complete the data delivery within five minutes for representative EO data traffic.
Summary
Proposes a similar thing to what petar talked about in the first meeting, where we both use groundstations, relay satellites and LEO mega-constellations.
Focuses mainly on routing:
Proposes to use location based addressing instead of ip-adressing, meaning the address of the satellite changes over time.
General Thoughts
Might be a good paper to site if we want to comment on the routing aspect of getting data down.
Annotations
| Highlight Color | Meaning |
|---|---|
| Red | Aim to Improve |
| Yellow | Neutral comments |
| Green | Aim to replicate |
| Blue | Further Reading |
- “very low latency include disaster management and emergency response (e.g., for floods, fires and earthquakes), forecasting for extreme weather conditions, remote monitoring and security (e.g., maritime smuggling/rescue, illegal fishing) and defense, where the EO data is only useful if it is successfully delivered in a very short time period [56].” Page
- applications
- Missions which would benefit from new downlink
- “free-space LEO→GEO laser links can achieve up…to 1.8Gbps [72] datarate,” Page - metric for leo to geo laser link
- “approach is still limited by the GEO→ground path with the speed less than 300Mbps. Moreover, the supported number of user-spacecrafts per GEO satellite relay is very limited (e.g., only 2 per GEO relay in TDRS [64]).” Page 2
- “to drive the simulation of LEO constellation, and emulate network software stack and traffic based on Mininet [11].” Page 2
- further_reading,simulation
- Possible use for sim
- “In particular, the average daily traffic generated by NASA’s EO system is about 27.9TB [60]. The present EO archive in European Space Agency (ESA) has exceeded 3 PB and it is foreseen that this volume will exceed 10 PB in few years [59].” Page 2
- facts,problem_analysis
- Some interesting facts for use in the problem analysis
- “low-latency, as the latency in above time-sensitive scenarios is expected to approach 1 minute or at least less than 5 minutes in particular [56];” Page 3
- further_reading
- Why less than 5 minutes?
- “(e.g., the per-satellite cost of Starlink is below $500K [20])” Page 4
- facts,problem_analysis
- Interesting price of starlink satellites
- “Specifically, we use ITU-Rpy [9] to simulate the impact of weather conditions on the atmospheric attenuation in slant and horizontal paths.” Page 8
- simulation,simulation_tools
- Sim tools
- “For each constellation, we follow a well-known +Grid topology [29], [43], [51] to interconnect each satellite, i.e., each satellite has at least five laser ISLs, two of which are connected to the two neighborhoods in the same orbit, and other two links are connected to the” Page 8
- further_reading,FSO
- For this paper the mega-constellation satellites have 5 FSO links. Maybe look into how many oneweb and starlink have