Yaakov J Stein

Tel Aviv University | TAU · Department of Computer Science

The telecommunications community has been so fixated on the question of whether we can afford not attaining 5G as soon as possible that no-one in the community seems to be asking whether we can afford attaining it. I study this issue along the axes of applicability, cost (to end-users and to mobile operators), energy usage (and carbon footprint),...

A method for measuring one-way delays in a communications network, the method comprising: maintaining a virtual clock state comprising information for converting times measured with respect to remote clocks into times as would be measured with respect to a local reference clock; registering, for each packet of the plurality of packets in a communic...

Apparatus for synchronizing a local clock to a master clock, the apparatus comprising: at least one port for receiving and transmitting packets; a local clock; and a packet inspector that uses time from the local clock to timestamp packets received at a port of the at least one port, copies timing information from the received packets if the packet...

A method of characterizing a communications channel between two communications nodes, the method comprising: determining at least one feature of a communications path between a first communications node and a second communications node; determining at least one feature of a communications path between the first communications node and a third commu...

Pseudowires (PWs) have become a common mechanism for tunneling traffic and may be found in unmanaged scenarios competing for network resources both with other PWs and with non-PW traffic, such as TCP/IP flows. Thus, it is worthwhile specifying under what conditions such competition is acceptable, i.e., the PW traffic does not significantly harm oth...

Apparatus for providing timing information, the apparatus comprising: a primary reference time clock (PRTC) that provides a reference time of day (ToD) and a reference frequency; a packet master clock that receives the ToD and reference frequency and is configured to distribute timing to a slave clock in accordance with a timing over packet procedu...

In the past few years, the terms software-defined networking (SDN) and network functions virtualisation (NFV) have emerged from nihility—SDN was coined circa 2009, NFV in 2012—to being the subjects of dozens of conferences, research groups (including the Internet Research Task Force’s SDNRG and NFVRG), industry groups, and open source communities....

Apparatus for monitoring a packet switched network, the apparatus comprising: at least one port for receiving and transmitting packets; a local clock; and a packet inspector that uses time from the local clock to timestamp packets received at a port of the at least one port, and additionally copies timing information from received timing distributi...

A method and system in which a Digital Subscriber Line Access Multiplexer (DSLAM) that is part of a DSL (Digital Subscriber Line) system is able to provide synchronous services to end user equipment connected to the DSLAM via a DSL link and Customer Premises Equipment (CPE). A sniffer device having direct or indirect access to a Primary Reference C...

A method and system in which a Digital Subscriber Line Access Multiplexer (DSLAM) that is part of a DSL (Digital Subscriber Line) system is able to provide synchronous services to end user equipment connected to the DSLAM via a DSL link and Customer Premises Equipment (CPE). A sniffer device having direct or indirect access to a Primary Reference C...

This document specifies the mapping and notification of defect states between a pseudowire (PW) and the Attachment Circuits (ACs) of the end-to-end emulated service. It standardizes the behavior of Provider Edges (PEs) with respect to PW and AC defects. It addresses ATM, Frame Relay, Time Division Multiplexing (TDM), and Synchronous Optical Network...

I semi-empirically study the social networking sites such as LinkedIn. Such sites enable users to maintain contact information of people they know and trust (their first degree connections or friends), and to discover the friends of their friends (their second degree connections), and to access the friends of the friends of their friends (their thi...

This document provides a security framework for Multiprotocol Label Switching (MPLS) and Generalized Multiprotocol Label Switching (GMPLS) Networks. This document addresses the security aspects that are relevant in the context of MPLS and GMPLS. It describes the security threats, the related defensive techniques, and the mechanisms for detection an...

If we have a high accuracy local frequency source, or a high time update rate, or a non-stringent time accuracy requirement, then we don't need to distribute frequency to obtain time. In other cases time distribution protocols such as NTP or 1588 typically need to lock a local clock's frequency to that of the primary clock. By combining a physical...

This document describes a pseudowire encapsulation for Time Division Multiplexing (TDM) bit-streams (T1, E1, T3, E3) that disregards any structure that may be imposed on these streams, in particular the structure imposed by the standard TDM framing.

A system and method for extending the distance that xDSL services are able to be provided to subscribers. A DSLAM located at a Central Office is connected to a general-purpose network, such as the Internet. The DSLAM is additionally connected to a first fiber optic transceiver. The first fiber optic transceiver is connected via a fiber optic link t...

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From the Publisher:Get a working knowledge of digital signal processing for computer science applications The field of digital signal processing (DSP) is rapidly exploding, yet most books on the subject do not reflect the real world of algorithm development, coding for applications, and software engineering. This important new work fills the gap in...

The authors study the optimal storage capacity of neural networks with discrete local constraints on the synaptic couplings Jij. Models with such constraints include those with binary couplings Jij=+or-1 or Jij=0, 1, quantised couplings with larger synaptic range, e.g. Jij=+or-1/L, +or-2/L, . . ., +or-1 and, in the limit, continuous couplings confi...

Summary form only given. Speech recognition systems tend to consist of the following modules: input (acquisition and acoustic processing); classification (phoneme/word recognition); language (lexical/syntactic/semantic) processing; output (actions to be performed); although in many systems these modules are further subdivided, in some systems some...

A variant of backpropagation that trains faster, gets caught in local minima less frequently, generalizes better for a given amount of training, and is specifically adapted to pattern recognition problems is presented. These abilities are demonstrated by simulations of an archetypal classification task

The average eigenvalue distribution $\rho(\lambda)$ of N*N real random asymmetric matrices $J_{ij}$ ($J_{ji} \ne J_{ij}$) is calculated in the limit $N \rightarrow \infty$. It is found that $\rho(\lambda)$ is uniform in an ellipse in the complex plane, whose real and imaginary axes are $1+\tau$ and $1-\tau$ respectively. The parameter \tau is given...

A novel classifier architecture is introduced which belongs to both hyperplane and hy- persphere families. The basic computational unit in the architecture is a perceptron whose input is augmented by its squared length. Traditional methods of training hy- perplane classifiers (perceptron training algorithm, backpropagation, etc.) function in the au...

VoIP has fallen short on the promise of providing a vehicle for delivering telephony traffic over IP networks. Fortunately, TDMoIP provides an alternative by transporting encapsulated TDM data over packet networks. Here's a look at how TDMoIP works.

Time Division Multiplexing over IP (TDMoIP) is a structure-aware method for transporting Time Division Multiplexed (TDM) signals using pseudowires (PWs). Being structure-aware, TDMoIP is able to ensure TDM structure integrity, and thus withstand network degradations better than structure-agnostic transport. Structure-aware methods can distinguish i...

This document defines extension to the Pseudowire Emulation Edge-to- Edge (PWE3) control protocol RFC 4447 and PWE3 IANA allocations RFC 4446 required for the setup of Time-Division Multiplexing (TDM) pseudowires in MPLS networks.

Shigeru Katagiri and various co-authors have (re)introduced a nonstandard error mea-sure which can be used in training almost any classifier. This measure is usually called MCE for Minimum Classification Error, and is often coupled with an equally nonstan-dard technique, known as GPD for Generalized Probabilistic Descent, for updating the classifie...

Techniques which may reduce the false alarm rate of sliding networks employed in ASR (automatic speech recognition) and OCR (optical character recognition) problems are reviewed. Such techniques include the use of hypersphere classifiers, training out of negatives, addition of garbage units, and exploitation of multiple networks. The combination of...