Mega-constellations have the potential for providing 6G Internet owing to unique advantage of global coverage. However, current satellite technologies are not omnipotent. There still many challenging problems that need be solved mega-constellations support 6G, e.g., efficient resource allocation, gratifying mobility management, and large-scale full-time TT&C (tracking, telemetry, command). This paper starts with a novel definition LEO brief review regarding typical mega-constellations,...

The satellite tracking, telemetry, and command system, or TT&C, is utilized to transmit the telemetry telecommand data, as well determine orbit. It lifeline of a satellite, thus its safety reliability are fundamental importance satellite. After years development, traditional TT&C technologies relatively mature, while there still many open problems be solved for long distance deep space explorers mega-constellation. In this article, we start with brief review regarding evolution system...

In recent years, in order to provide worldwide broadband Internet access services, many mega-constellation projects have been proposed. Traditional ground-based and space-based telecommand systems only rely on a single path for data transmission, which is vulnerable once the fails. This paper utilizes inter-satellite-links (ISLs) constellation network reduce risk of transmission failure, proposes failure-tolerant low-latency redundant multi-path routing algorithm (RMPR). RMPR transmits...

Satellite constellations are promising in enabling the global Internet. However, increasing constellation size also complicates tracking, telemetry and command (TT&C) systems. Traditional ground-based space-based approaches have encountered significant obstacles due to, e.g., limited satellite visible arc long transmission delay. Considering fast development of intersatellite communications, synergy among multiple connected satellites can be exploited to facilitate TT&C system designs. This...

In current Mars relay communications, the Consultative Committee for Space Data Systems (CCSDS) Proximity-1 protocol is simple and efficient but it exhibits low flexibility in optimal access orbiter selection. Once connected with first successful hailing orbiter, rover would not switch to other better orbiters until end of that connection, which makes difficult provide more convenient data services. The entire system cost essential selection, includes both links' transmission concerned...

Network architecture is key to mobile communication networks, which determines network resource efficiency, service modalities, and industry trends. In the future 6G network, ever-changing scenarios, refined classification, diversified elements will make design deployment of more difficult complex. Further, digital twin, as a real-time interactive mapping system, can create mirror image physical space in world provide strong support for mathematical modeling architecture. Therefore, this...

Summary The Mars relay communication services have played an important role on the scientific data transmission for several surface exploration missions. However, such technologies based CCSDS Proximity‐1 protocols only support one single user's access to orbiter at session. In future deep space missions, there would be more rovers and facilities surface, which requires a multiple method with high efficiency low resource occupation. this article, we propose distributed serial scheduling...

In recent years, various mega-constellation plans have been issued and the number of planned satellites has increasing. However, boundary satellite that existing tracking, telemetry command (TT&C) resources can support never analyzed. This paper discusses TT&C capacity mega-constellations for first time. Under requirement instantaneity reliability system, constellation be supported based on inter-satellite link is explored. We establish model N*D/D/1 queuing model. Then we analyze...

This fact sheet describes our proposed method for the video track of Challenge on Learned Image Compression (CLIC) 2024. Our scheme follows typical hybrid coding framework with advanced techniques in motion estimation, context mining, and spatial-temporal super-resolution to enhance rate-distortion performance, particularly at low bitrates.

We present UniMIC, a universal multi-modality image compression framework, intending to unify the rate-distortion-perception (RDP) optimization for multiple codecs simultaneously through excavating cross-modality generative priors. Unlike most existing works that need design and optimize from scratch, our UniMIC introduces visual codec repository, which incorporates amounts of representative directly uses them as basic various practical applications. Moreover, we propose multi-grained...

The safety of submerged buoy is higher than traditional buoy. most important problem for that signal will be attenuated greatly due to ocean wave fluctuation and seawater. On the basis model, propagation characteristics electromagnetic in seawater channel analyzed this letter. It includes properties across air-sea interface. results show VHF frequency band, first order sea level water depth less 10 cm are acceptable

We have witnessed the rapid development of learned image compression (LIC). The latest LIC models outperformed almost all traditional standards in terms rate-distortion (RD) performance. However, time complexity model is still underdiscovered, limiting practical applications industry. Even with acceleration GPU, struggle long coding time, especially on decoder side. In this paper, we analyze and test a few prevailing representative models, compare their codecs including H.265/HEVC intra...

Remote medical diagnosis has emerged as a critical and indispensable technique in practical systems, where data are required to be efficiently compressed transmitted for by either professional doctors or intelligent devices. In this process, large amount of redundant content irrelevant the is subjected high-fidelity coding, leading unnecessary transmission costs. To mitigate this, we propose diagnosis-oriented image compression, special semantic compression task designed scenarios, targeting...

Remote medical diagnosis has emerged as a critical and indispensable technique in practical systems, where data are required to be efficiently compressed transmitted for by either professional doctors or intelligent devices. In this process, large amount of redundant content irrelevant the is subjected high-fidelity coding, leading unnecessary transmission costs. To mitigate this, we propose diagnosis-oriented image compression, special semantic compression task designed scenarios, targeting...

For ocean buoys, the most effective information transmission link is space-based link. Traditional buoys all float on surface, by contrast, submerged have a higher security. However, since it submerges below sea biggest problem high dynamic attenuation of seawater channel. This paper proposes novel method which can overcome highly channel characteristics. The state predicted reflected wave received an assisting receiver. According to states, phase shift and amplitude caused are...