180 Park Ave - Building 103
Florham Park, NJ
Contributor to: applied probability and algorithmic methods; stochastic processes; queueing theory; fluid flows; performance models for voice, data, packet, broadband video, and wireless technologies.
Ph.D. (Mathematics of Operations Research); M.Sc. (Statistics)
Former Positions: Chief Scientist, Bellcore; District Manager, Bellcore; MTS, Bellcore; MTS Bell Labs; Asst Professor Drexel Univ.
Professional: Invited Member, International Federation for Information Processing (IFIP) WG 7.3 on Performance; Member IMS, INFORMS, IISA; Editor, Stochastic Models.
Author: Introduciton to Matrix Analytic Methods in Stochastic Modeling (with G. Latouche), ASA/SIAM, 1999
Other: 2001 Ramanujan Memorial Lecturer; 2004 INFORMS Wagner Prize Finalist.
Modeling and Characterization of Large-Scale Wi-Fi Traffic in Public Hot-Spots
Amitabha Ghosh, Rittwik Jana, Vaidyanathan Ramaswami, James Rowland, N Shankaranarayanan
Infocom 2011,
2011.
[BIB]
{Server side measurements from several Wi-Fi hotspots
deployed in a nationwide network over different types of
venues from small coffee shops to large enterprises are used to
highlight differences in traffic volumes and patterns. We develop
a common modeling framework for the number of simultaneously
present customers. Our approach has many novel elements: (a)
We combine statistical clustering with Poisson regression from
Generalized Linear Models to fit a non-stationary Poisson process
to the arrival counts and demonstrate its remarkable accuracy;
(b) We model the heavy tailed distribution of connection durations
through fitting a Phase Type distribution to its logarithm
so that not only the tail but also the overall distribution is
well matched; (c) We obtain the distribution of the number
of simultaneously present customers from an Mt/G/infty queuing
model using a novel regenerative argument that is transparent and
avoids the customarily made assumption of the queue starting
empty at an infinite past; (d) Most importantly, we validate
our models by comparison of their predictions and confidence
intervals against test data that is not used in fitting the models.}
Applied Probability and Statistics: Some challengs and Opportunities
Vaidyanathan Ramaswami
Narosa Publications, India,
2011.
[DOC]
[BIB]
{The last three decades have seen major strides in statistical methodlogies. But many areas of applied probability are yet to take advantage of these. We illustrate the opporunties presented for both applied probability and statistics research through a set of examples from our recent attempts to infuse more current statistical methods into our applied probability anlayses.}
Limited Chain Relay With Virtual Peer For Multimedia Distribution,
November 27, 2012
A method includes at a first customer premises equipment (CPE) device coupled to a multimedia distribution network, generating a first request for multimedia content. The method also includes sending the first request to a network node of the multimedia distribution network. The method further includes receiving the multimedia content from a virtual peer located at the network node and storing the multimedia content at the first CPE device. The method also includes receiving a message via the multimedia distribution network, the message indicating a transmission of a second request for the multimedia content by a second customer premises equipment (CPE) device. The method further includes transmitting at least a portion of the stored multimedia content to the second CPE device.
Method And Apparatus For Routing Data,
January 10, 2012
A method and apparatus for handling internet access telephone calls made via cable company telephone services. A head end data terminal receives cable signals and converts them into individual signals. An intelligent switch detects signals destined for an internet service provider and routes those signals on a separate path to the internet service provider. A central switch routes the other signals along a telephone network. A computer program can control the steps of receiving cable signals, converting them into voice band signals, routing the signals that are not for the intended recipient to a central switch, multiplexing the signals for the intended recipient together, and sending the multiplexed signals to the intended recipient.
Method and apparatus for routing data,
May 6, 2008
A method and apparatus for handling internet access telephone calls made via cable company telephone services. A head end data terminal receives cable signals and converts them into individual signals. An intelligent switch detects signals destined for an internet service provider and routes those signals on a separate path to the internet service provider. A central switch routes the other signals along a telephone network. A computer program can control the steps of receiving cable signals, converting them into voice band signals, routing the signals that are not for the intended recipient to a central switch, multiplexing the signals for the intended recipient together, and sending the multiplexed signals to the intended recipient.
Method for preventing overload condition in a circuit switched arrangement,
August 29, 2006
An arrangement where connections between a terminal and a switch are effected through a serial connection of shared, overloadable, resources, and where conventionally each of the resources has a given number of communication channels, provides for effective congestion control by converting one or more of the communications channels to one or more groups of enhanced signaling channels. The congestion control is effected by employing the enhanced signaling channels, which can carry audible signals, to determine whether to set up requested calls, based on a preselected congestion control process.
Method for preventing overload condition in a circuit switched arrangement,
June 27, 2006
Congestion problems in networks are alleviated with a method that works toward insuring that unused capacity will always exist in elements of a network that are resources which are shared by a plurality of users and which, consequently, can be overloaded. In response to each request to establish a connection over a path in the network, pursuant to a predetermined algorithm the method services the request, declines to service the request, or services the request after dropping an established connection. In one embodiment, when unused capacity on the path is above a first preselected level, all requests are serviced. When unused capacity falls below a second preselected threshold, no requests are serviced. When unused capacity is between the first and second thresholds, an existing data connection is dropped if a requested connection is a voice connection and the number of existing data connections exceeds a preselected threshold.
Method for preventing overload condition in a circuit switched arrangement,
January 17, 2006
A method for alleviating congestion problems in prior art networks delays provision of dial tone signals to terminals that are, likely, carrying out a re-dial attempt in excess of a preselected number of re-dial attempts. A determination that the terminal seeking to establish a connection is likely carrying out a re-dial attempt may be based on numerous factors, such as the time since the last time the terminal desired to establish a call, the duration of the last call, etc. The delay that is imposed is, advantageously, sensitive to the number of times the terminal has attempted a re-dial, and on other conditions, such as the cause of the failure to establish a connection, network congestion conditions, etc. In imposing the dial tone delay, identities of the terminals that are to receive a delayed dial tone are placed in a FIFO queue.
Method for providing a phone conversation recording service,
January 17, 2006
The present invention is a method and system for recording a communication over a public network upon the request of a communicating party. The request is received for the recording service from a first communicating party and an identification number, received from the first communicating party, is verified. A number is received for a second communicating party from the first communicating party and a connection for a communication between the first and second communicating parties is established. Finally a recording of the communication is made and, after the completion of the communication is detected, the recording is converted to a standard audio file. The system may provide additional information with the recording, such as a time/date stamp and the telephone numbers associated with the communication, in order to authenticate the call
Method For Preventing Overload Condition In A Circuit Switched Arrangement,
November 30, 2004
Congestion problems in networks are alleviated with a method that works toward insuring the unused capacity will always exist in elements of a network that are resources which are shared by a plurality of users and which, consequently, can be overloaded. In response to each a request to establish a connection over a path in the network, pursuant to a predetermined algorithm method either services the request, declines to service the request, or services the request after dropping an established connection. In one embodiment, when unused cavity on the path is above a preselected level, all requests are services. What unused capacity falls below a preselected threshold, a probabilistic approach is taken as to service the request or not, and as whether to drop an existing call in order to service the request.
Method for preventing overload condition in a circuit switched arrangement,
May 4, 2004
A method that alleviates congestion problems in prior art networks by insuring that selected classes of calls have a reserved capacity, thus insuring a capability to service at least the selected level of traffic. In an illustrated embodiment, a selected capacity is reserved for voice calls, in contrast to data calls. When a connection request is made and there is unoccupied capacity, a voice call is always serviced, but a data call is serviced only if the number of established data connections is less than capacity of the path required for establishing a connection for the request, minus the capacity reserved for voice call.
