Overhead Bytes Research Articles

Privacy-Preserving Multi-Party Cross-Chain Transaction Protocols

Cross-chain transaction technologies have greatly promoted the scalability of cryptocurrencies, which then facilitates the development of Metaverse applications. However, existing solutions rely heavily on centralized middleware (notary) or smart contracts. These schemes lack privacy considerations, and users’ cross-chain transactions are easy to master by other parties. Some signature-based payment schemes have good privacy but do not support multi-party cross-chain protocols or rely heavily on some time assumptions. The uncertainty of user behavior makes it difficult to design a secure multi-party cross-chain protocol. To solve these problems, we investigate how to design a secure multi-party cross-chain transaction protocol with offline tolerance. We propose a new signature algorithm called the pre-adaptor signature scheme, an extension of the adaptor signature scheme. The pre-adaptor signature scheme combines the multi-signature and adaptor signature schemes, which can realize the secret transmission channel between multiple parties. To provide offline tolerance, we encode our protocol into the P2SH script. Our protocol provides better privacy due to no dependence on smart contracts. The performance evaluation was conducted with ten participants. For each participant of our cross-chain protocol, the initialization and execution process can be performed in 3 milliseconds and with 6 k bytes of communication overhead at most. The cost increases linearly with the increase in the number of participants.

Multi-COBS: A Novel Algorithm for Byte Stuffing at High Throughput

Framing methods are used to break a data stream into packets in most digital communications. The use of a reserved symbol to denote the frame boundaries is a popular practice. This end-of-frame (EOF) marker should be removed from the packet content in a reversible manner. Many strategies, such as the bit and byte stuffing processes employed by high-level data link control (HDLC) and Point-to-Point Protocol (PPP), or the Consistent Overhead Byte Stuffing (COBS), have been devised to perform this goal. These bit and byte stuffing algorithms remove the reserved EOF marker from the packet payload and replace it with some extra information that can be used to undo the action later. The amount of data added is called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">overhead</i> and is a figure-of-merit of such algorithms, together with the encoding and decoding speed. Multi-COBS, a new byte stuffing algorithm, is presented in this paper. Multi-COBS provides concurrent encoding and decoding, resulting in a performance improvement of factor four or eight in common word-based digital architectures while delivering an average and worst-case overhead equivalent to the state-of-the-art. On the reference 28-nanometer field programmable gate array (FPGA) (Artix-7), Multi-COBS achieves a throughput of 6.6 Gbps, instead of 1.7 Gbps of COBS. Thanks to its parallel elaboration capability, Multi-COBS is ideal for digital systems built in programmable logic as well as modern computers.

Wearable, Multimodal, Biosignal Acquisition System for Potential Critical and Emergency Applications.

For emergency or intensive-care units (ICUs), patients with unclear consciousness or unstable hemodynamics often require aggressive monitoring by multiple monitors. Complicated pipelines or lines increase the burden on patients and inconvenience for medical personnel. Currently, many commercial devices provide related functionalities. However, most devices measure only one biological signal, which can increase the budget for users and cause difficulty in remote integration. In this study, we develop a wearable device that integrates electrocardiography (ECG), electroencephalography (EEG), and blood oxygen machines for medical applications with the hope that it can be applied in the future. We develop an integrated multiple-biosignal recording system based on a modular design. The developed system monitors and records EEG, ECG, and peripheral oxygen saturation (SpO2) signals for health purposes simultaneously in a single setting. We use a logic level converter to connect the developed EEG module (BR8), ECG module, and SpO2 module to a microcontroller (Arduino). The modular data are then smoothly encoded and decoded through consistent overhead byte stuffing (COBS). This developed system has passed simulation tests and exhibited proper functioning of all modules and subsystems. In the future, the functionalities of the proposed system can be expanded with additional modules to support various emergency or ICU applications.

RSD: Rate-Based Sync Deferment for Personal Cloud Storage Services

Cloud storage services, such as Dropbox, Google Drive, and OneDrive, to cite a few, are becoming an increasingly “vital” tool in our everyday life. Unluckily, these services can incur large network overhead in different usage scenarios. To reduce it, these systems utilize several techniques, such as source-based deduplication, chunking, delta compression, and so on. One of these techniques is sync deferment, which relies on the packing of updates to intentionally defer the synchronization process for some time, and increase the volume of useful data per overhead byte. The scientific literature has shown this technique to be very helpful, though there are still some limitations on current solutions. To resolve them, we present here a new adaptive sync deferment method, which is comparable to the current state of the art in terms of network overhead, but is also able to minimize the file synchronization time up to 12 times.

VoIP transmission mechanism based on TCP

As the widespread employment of firewalls on the Internet, user datagram protocol (UDP) based voice over Internet protocol (VoIP) system will be unable to transmit voice data. This paper proposed a novel method to transmit voice data based on transmission control protocol (TCP). The method adopts a disorder TCP transmission strategy, which allows discontinuous data packets in TCP queues read by application layer directly without waiting for the retransmission of lost data packets. A byte stream data boundary identification algorithm based on consistent overhead byte stuffing algorithm is designed to efficiently identify complete voice data packets from disordered TCP packets arrived so as to transmit the data to the audio processing module timely. Then, by implementing the prototype system and testing, we verified that the proposed algorithm can solve the high time delay, jitter and discontinuity problems in standard TCP protocol when transmitting voice data packets, which caused by its error control and retransmission mechanism. We proved that the method proposed in this paper is effective and practical.

Reliable Connectionless Transport Protocol for Fast Message Delivery

TCP and UDP are the most used transport layer protocols in computer networks. These two protocols are used for almost all types of data transmission including files, messages, real-time streaming of media etc. In cases where loss of a single data unit then it makes the entire data transfer useless such as file transfer, TCP is used because it ensures reliability. UDP is unreliable and can be used where little loss is acceptable and sender does not need a conformation of successful delivery to the receiver. In past decade a large variety of network applications has emerged requiring different requirements for transport layer protocol. Currently in cases where a message needs to be sent to a destination and sender needs confirmation of successful delivery of the message TCP must be used. However TCP requires 3 way handshakes and has large over head of header bytes which may be not required in such cases. This paper proposes a transport layer protocol that is connection less like UDP and has very less header overhead bytes and ensures reliability of transmission. This protocol saves from connection establishment phase and overhead of additional header bytes. From calculation it can be observed that this protocol improves efficiency of transmission in certain cases. Keywords: Network, Protocol, Reliable, RCTP, TCP, Transport Layer, UDP

Quantitative analysis of enhanced mobile IP

As the popularity of mobile computing grows, the associated protocols and their scalability are subject to much closer scrutiny. Mobile IP relies heavily on the use of IP-to-IP tunneling, requiring 20 bytes of overhead for every packet routed to or from a mobile node, assuming reverse tunneling is enabled. The goal of this research was to show that enhanced mobile IP (EMIP) eliminated the overhead by replacing tunneling with network address port translation (NAPT) without significantly impacting other performance factors. EMIP was implemented and benchmarks were used to compare EMIP and mobile IP. The percentage of overhead with EMIP approached zero as the number of packets exchanged increased, while the percentage of overhead with mobile IP remained constant. Once three or more round-trip packets were exchanged, the overhead of EMIP was less than mobile IP, and when 1000 round-trip packets were exchanged, EMIP resulted in a bandwidth savings of almost 40,000 bytes. To achieve the bandwidth savings, EMIP introduced a one-time delay in session startup ranging from 160 to 260 ms when compared to mobile IP, but it does not significantly impact the scalability or overall performance of the protocol. Therefore, the decrease in bandwidth consumed by the overhead of EMIP greatly outweighs the one-time delay and additional memory required

Two-Way Time and Frequency Transfer Using SONET/SDH

This article presents a novel design for an optical system for time-and-frequency transfer via optical fibres, developed at the Telecommunication Laboratory of Chunghwa Telecom Co. The system includes a transceiver, a controller, and a timing circuit. We determined the number of unused overhead bytes of the SONET/SDH frame, in transmitting a timing signal. The system completed the loop-back test in temperature-controlled conditions, at 23 ± 0.3°C. Experimental results show that short-term time stability can be achieved at 5ps and long-term frequency stability is better than 1 × 10-14, regardless of whether the loop-back is a 5-m or 35-km long optical fibre. Moreover, the delay variation in the 35-km loop-back test is less than 1.4 ns.

Consistent overhead byte stuffing

Byte stuffing is a process that encodes a sequence of data bytes that may contain illegal or reserved values, using a potentially longer sequence that contains no occurrences of these values. The extra length is referred to here as the overhead of the encoding. To date, byte stuffing algorithms, such as those used by SLIP, PPP, and AX.25, have been designed to incur low average overhead, but little effort has been made to minimize their worst-case overhead. However, there are some increasingly popular network devices whose performance is determined more by the worst case than by the average case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the current practice is to set the maximum packet size artificially low so that no packet, even after worst-case overhead, can exceed the transmission time limit. This paper presents a new byte stuffing algorithm, called consistent overhead byte stuffing (COBS), which tightly bounds the worst-case overhead. It guarantees, in the worst case, to add no more than 1 byte in 254 to any packet. For large packets, this means that their encoded size is no more than 100.4% of their pre-encoding size. This is much better than the 200% worst-case bound that is common for many byte stuffing algorithms, and is close to the information-theoretic limit of about 100.07%. Furthermore, the COBS algorithm is computationally cheap, and its average overhead is very competitive with that of existing algorithms.

The impact of mapping wander on the performance of SDH AU-4 and TU-3 uniform pointer processors

Pointer processors in Synchronous Optical Networks (SONET)/Synchronous Digital Hierarchy (SDH) networks may be placed into three categories: fixed threshold, adaptive threshold modulation and uniform. Fixed threshold pointer processors produce gapped pointer sequences during SONET/SDH holdover mode, when one or more node's clock has lost its synchronization reference, as a result of the periodic effects of the SONET/SDH frame overhead bytes. These gapped pointer sequences cause mapping wander in the underlying Plesiochronous Digital Hierarchy (PDH) payloads. Uniform pointer processors can smooth the gapped pointer effects caused by the Synchronous Transport Module (STM), Administrative Unit (AU) and Tributary Unit (TU) overhead bytes. However, uniform pointer processors cannot remove the additional gapped pointer effects caused by the Virtual Container (VC) overhead bytes. Mathematical analysis and simulation results, for fixed threshold pointer processors in SDH networks where VC-3 uses TU-3 to transport an E3-rate PDH payload or VC-4 uses AU-4 to transport an E4-rate PDH payload, illustrate the wander caused by the gapped pointer effects. A proposed uniform pointer processor algorithm shows the residual mapping wander caused by the VC-3 and VC-4 overhead bytes. Finally, a lower bound on the Maximum Time Interval Error (MTIE) that can be achieved with a uniform pointer processor is calculated for these two cases.

A study of the burstiness of combined MPEG video and audio bitstreams

Variable bit rate (VBR) video is very bursty and its transportation over ATM networks is problematic because bandwidth has to be reserved in advance. Studies have shown that VBR video exhibits statistical self-similarity: it displays structural similarities across a wide range of time scales. To date, studies on the burstiness of MPEG compressed bitstreams have been conducted on the video part only; the audio part has been neglected because of its constant bit rate nature. Furthermore, the change in burstiness of MPEG data which occurs after they have been converted to MPEG-2 transport and ATM bitstreams has not been investigated; a considerable amount of overhead bytes is introduced during the conversion. This paper reports on a study on the burstiness of combined MPEG-1 audio and video bitstreams as found on commercial Video CDs, and the burstiness of these combined bitstreams after they have been converted to MPEG-2 transport and ATM layer bitstreams. We found that there is no increase in burstiness in both situations.

Consistent overhead byte stuffing

Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal' or 'reserved' values into a potentially longer sequence that contains no occurrences of those values. The extra length is referred to in this paper as the overhead of the algorithm.To date, byte stuffing algorithms, such as those used by SLIP [RFC1055], PPP [RFC1662] and AX.25 [ARRL84], have been designed to incur low average overhead but have made little effort to minimize worst case overhead.Some increasingly popular network devices, however, care more about the worst case. For example, the transmission time for ISM-band packet radio transmitters is strictly limited by FCC regulation. To adhere to this regulation, the practice is to set the maximum packet size artificially low so that no packet, even after worst case overhead, can exceed the transmission time limit.This paper presents a new byte stuffing algorithm, called Consistent Overhead Byte Stuffing (COBS), that tightly bounds the worst case overhead. It guarantees in the worst case to add no more than one byte in 254 to any packet. Furthermore, the algorithm is computationally cheap, and its average overhead is very competitive with that of existing algorithms.

Forward error correcting codes in synchronous fiber optic transmission systems

This paper proposes forward error correcting (FEC) code for synchronous digital hierarchy (SDH) fiber optical transmission systems. They are (18880, 18865) and (2370, 2358) shortened Hamming codes and are encoded at the multiplex-section layer; the check bits are embedded in auxiliary multiplex-section overhead (MSOH) bytes. The codes realize general circuit configurations regardless of the transmission speed or path-size, perfect compatibility with SDH format, suppressed processing delay accumulation, and decrease the chance of line-switching in the case of signal degradation. To ensure that the various requirements of each network-provider such as customized usage of SOH bytes and affordable circuit scale could be satisfied, a trial circuit board was constructed on the programmable hardware called PROTEUS, which enables flexible operation in terms of code-selection and check bit area. We actually confirm error-correcting capability through the first STM-64 FEC-coded-optical transmission experiment. The statistics of error occurrence in the optical transmission line are also studied. The result indicates that the proposed codes are effective in optical transmission systems if the BER is limited by optical noise and dispersion.

Effects of fixed frequency clock offsets in synchronous digital hierarchy networks

AbstractSDH networks require synchronous clocking in order to minimize network wander and jitter. In practice, the clocks in SDH networks are not ideal and thus are not all perfectly synchronous. The operation of SDH networks with non‐ideal clocks results in undesirable wander and jitter effects. Two different philosophies are being used to minimize these undesirable synchronization effects in SDH networks. In Europe, where it is difficult to tighten clock specifications due to the multinational synchronization environment, desynchronizer designs are made more robust. In North America, where Synchronous Optical Network (SONET) is used, the specifications of both the clocks and the synchronization distribution are being tightened. Even with these different approaches, non‐ideal synchronization effects still exist in SDH networks. In particular, the STM‐N. AU, and TU overhead bytes cause gapped pointer effects when traditional fixed threshold pointer processors are used. Another type of pointer processor, a uniform pointer processor, can remove the gapped pointer effects caused by the STM‐N, AU, and TU overhead bytes. Additionally, a compensating desynchronizer may be used to remove the gapped effects caused by the VC overhead bytes. If these gapped effects are not removed. then they cause jitter and wander in a reconstructed PDH signal. This paper focuses on the case where the SDH network clocks have fixed frequency offsets. An El‐rate (2048 kbit/s) payload, which is transported over a network consisting of SDH and PDH islands, is used to show the effects of this non‐ideal clocking in SDH networks. In theory, clock frequency differences in SDH networks are accommodated by the pointer processor mechanism without slips (i.e. losing or repeating data). In practice, non‐ideal synchronization may still cause slips.

A two chips set — full parallel process for framing equipment in sdh compatible radiolinks

ccitt has standardised a new synchronous interface named sdh (Synchronous Digital Hierarchy). Considering the importance of transmission-medium compatibility between radio and optical fibre systems, Alcatel Telspace has developed sdh based digital radio systems. In order to provide a direct access to all the section overhead bytes (soh) in the stm-1 frame and the insertion/extraction of radio overhead bytes for media specific usage, two cmos integrated circuits were designed, operating in a parallel process at 40 MHz data rate, in order to respect a full transparency criterion, necessary for a short synchronisation time on the whole radio link.

Inherent pattern jitter of STM-64 format signal and a reduction method

The inherent pattern jitter of the STM-64 format signal is found to be increased by the DC level fluctuation of incoming data and the output power variation of the timing tank in the section overhead bytes which become longer than the time constant of the timing tank. This pattern jitter is reported to be success fully suppressed by using an already proposed timing recovery circuit with a 1/2T differentiator, which operates as a pattern transformer.

Design and characterization of an error-correcting code for the SONET STS-1 tributary

The authors have designed and characterized a single-error-correcting (SEC), double-error-detecting (DED) code applicable to the STS-1 SONET format. They show that if two of the presently unallocated bytes in the path overhead field of STS-1 are assigned for error-correction coding (ECC), a (6208, 6195) shortened extended Hamming code can be implemented using as few as 660 gates plus a 1-kbyte RAM IC, achieving (O8.6*10/sup -3/ P/sub 2//sup 2/) BER reduction with 139 mu s of signal delay. The authors explain how the existing BIP-8 error-monitoring byte of the STS-1 format could be integrated with the proposed ECC so that a net allocation of only one new STS-1 overhead byte is required for both error monitoring and error correction. The implementation method is such that all path, line, and section overhead functions in SONET can be performed at intermediate sites without requiring ECC decoding. The authors consider application alternatives and describe the forward-error-correction (FEC) circuit design and trial results. System issues are covered, including network delay, effects of error extension on BER, addition of double-error detection, performance monitoring, and options for intelligent network control and management of FEC functions. Codes related to their path-level design that are applicable to a number of other strategies for applying FEC in SONET are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>