Author

# Linda Zeger

Bio: Linda Zeger is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Linear network coding & Network packet. The author has an hindex of 12, co-authored 27 publications receiving 329 citations.

##### Papers

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01 Sep 2013TL;DR: The results show that network coding can provide users in mobile environments a higher quality of service by enabling the use of multiple network technologies and the capability to overcome packet losses due to lossy, wireless network connections.

Abstract: Existing mobile devices have the capability to use multiple network technologies simultaneously to help increase performance; but they rarely, if at all, effectively use these technologies in parallel. We first present empirical data to help understand the mobile environment when three heterogeneous networks are available to the mobile device (i.e., a WiFi network, WiMax network, and an Iridium satellite network). We then propose a reliable, multi-path protocol called Multi-Path TCP with Network Coding (MPTCP/NC) that utilizes each of these networks in parallel. An analytical model is developed and a mean-field approximation is derived that gives an estimate of the protocol's achievable throughput. Finally, a comparison between MPTCP and MPTCP/NC is presented using both the empirical data and mean-field approximation. Our results show that network coding can provide users in mobile environments a higher quality of service by enabling the use of multiple network technologies and the capability to overcome packet losses due to lossy, wireless network connections.

52 citations

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TL;DR: In this article, a cross-layer approach is proposed to aid in developing a cooperative solution using multi-packet reception (MPR), network coding (NC), and medium access (MAC).

Abstract: We design a cross-layer approach to aid in developing a cooperative solution using multi-packet reception (MPR), network coding (NC), and medium access (MAC). We construct a model for the behavior of the IEEE 802.11 MAC protocol and apply it to key small canonical topology components and their larger counterparts. The results obtained from this model match the available experimental results with fidelity. Using this model, we show that fairness allocation by the 802.11 MAC can significantly impede performance; hence, we devise a new MAC that not only substantially improves throughput, but provides fairness to flows of information rather than to nodes. We show that cooperation between NC, MPR, and our new MAC achieves super-additive gains of up to 6.3 times that of routing with the standard 802.11 MAC. Furthermore, we extend the model to analyze our MAC's asymptotic and throughput behaviors as the number of nodes increases or the MPR capability is limited to only a single node. Finally, we show that although network performance is reduced under substantial asymmetry or limited implementation of MPR to a central node, there are some important practical cases, even under these conditions, where MPR, NC, and their combination provide significant gains.

37 citations

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01 Oct 2010TL;DR: It is shown that the initial transmissions and the back-filling process can be greatly sped up through a combination of network coding and multi-packet reception, and it is demonstrated that network coding can substitute for some degree of MPR and achieve the same, or almost, performance as the higher degree ofMPR without network coding.

Abstract: We consider throughput and delay gains resulting from network coding used to complement multi-packet reception in a fully connected network with broadcast traffic. The network is comprised of N nodes, J of which have data packets to be distributed to all other nodes. Owing to half-duplex constraints, a transmitting node is not able to receive data from other transmitting nodes in the same time slot. This requires a node to be back-filled with the information that it is missing. We consider singlepacket reception, (for which network coding alone yields no gain), multi-packet reception without network coding, and combined multi-packet reception and network coding. We show that the initial transmissions and the back-filling process can be greatly sped up through a combination of network coding and multi-packet reception. In particular, we show that MPR capability of 2 will not reduce the total delivery time for packets within a data network unless network coding is used. We also demonstrate that a combination of network coding and multi-packet reception can reduce this time by a factor of m, where m is the MPR capability of the system. We demonstrate that network coding can substitute for some degree of MPR and achieve the same, or almost the same, performance as the higher degree of MPR without network coding. In effect, network coding allows almost double the traffic for a given level of MPR.

29 citations

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18 Oct 2012TL;DR: In this paper, network coding and multiple packet reception (MPR) are used together to improve message dissemination speed in a wireless network using half duplex communication, where MPR is used to initially distribute data packets from a number of source nodes in the network to the other nodes of the network.

Abstract: Network coding and multiple packet reception (MPR) are used together to improve message dissemination speed in a wireless network using half duplex communication. In at least one embodiment, MPR is used to initially distribute data packets from a number of source nodes in the network to the other nodes of the network. Network coding techniques may then be used to perform backfilling within the network to supply data packets to the source nodes that were originally missed due to the half duplex constraint.

28 citations

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TL;DR: It is demonstrated that with SMART, counter to conventional wisdom, the average user's QoE improves slightly as the number of users increases, and SMART's algorithmic simplicity enables multicast transmissions that on average take fewer than 2 feedback rounds to complete.

Abstract: We introduce a novel feedback protocol, called SMART, for wireless broadcast networks that use linear network coding. We consider transmission of packets from a single source to many receivers over a single-hop broadcast erasure channel with heterogeneous links. We propose a predictive model to minimize feedback as well as extraneous data transmissions by the source. In addition, we use the method of types to provide a lower bound for the expected total transmission time, and use simulations to show that our protocol operates close to this lower bound. We show that with SMART, counter to conventional wisdom, the average user's QoE improves slightly as the number of users increases. We demonstrate that SMART's algorithmic simplicity enables multicast transmissions that on average take fewer than 2 feedback rounds to complete. We show the favorable scalability of our technique with the number of users, which enables reliable quality of experience. We also show the robustness of this scheme to uncertainty in the number of receiving nodes, and packet erasure probability, as well as to partial loss of the feedback. Furthermore, we show that SMART performs nearly as well as an omniscient transmitter that requires no feedback.

24 citations

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01 Jan 2014

TL;DR: This paper shows the first explicit algorithm which can construct strongly k-secure network coding schemes, and it runs in polynomial time for fixed k.

Abstract: We say that a network coding scheme is strongly 1-secure if a source node s can multicast n field elements {m1, · · · ,mn} to a set of sink nodes {t1, · · · , tq} in such a way that any single edge leaks no information on any S ⊂ {m1, · · · ,mn} with |S| = n − 1, where n = mintimax-flow(s, ti) is the maximum transmission capacity. We also say that a strongly h-secure network coding scheme is strongly (h + 1)secure if any h + 1 edges leak no information on any S ⊂ {m1, · · · ,mn} with |S| = n − (h + 1). In this paper, we show the first explicit algorithm which can construct strongly k-secure network coding schemes. In particular, it runs in polynomial time for fixed k.

263 citations

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01 Jan 1993

TL;DR: The paper is presented in two parts: the first, appearing here, summarizes the major results and treats the case of high transmission rates in detail; the second, to appear in the subsequent issue, treats the cases of low transmission rates.

Abstract: New lower bounds are presented for the minimum error probability that can be achieved through the use of block coding on noisy discrete memoryless channels. Like previous upper bounds, these lower bounds decrease exponentially with the block length N . The coefficient of N in the exponent is a convex function of the rate. From a certain rate of transmission up to channel capacity, the exponents of the upper and lower bounds coincide. Below this particular rate, the exponents of the upper and lower bounds differ, although they approach the same limit as the rate approaches zero. Examples are given and various incidental results and techniques relating to coding theory are developed. The paper is presented in two parts: the first, appearing here, summarizes the major results and treats the case of high transmission rates in detail; the second, to appear in the subsequent issue, treats the case of low transmission rates.

247 citations

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30 Jan 2013TL;DR: In this article, techniques, devices, systems, and protocols related to data transfer between communication nodes via multiple heterogeneous paths are described, where network coding may be used to improve data flow and reliability in a multiple path scenario.

Abstract: Techniques, devices, systems, and protocols are disclosed herein that relate to data transfer between communication nodes via multiple heterogeneous paths. In various embodiments, network coding may be used to improve data flow and reliability in a multiple path scenario. Transmission control protocol (TCP) may also be used within different paths to further enhance data transfer reliability. In some embodiments, multiple levels of network coding may be provided within a transmitter in a multiple path scenario, with one level being applied across all paths and another being applied within individual paths.

84 citations

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TL;DR: In this article, the authors explore properties and applications of the principal inertia components (PICs) between two discrete random variables and show that they can be used to characterize information-theoretic limits of certain estimation problems.

Abstract: We explore properties and applications of the principal inertia components (PICs) between two discrete random variables $X$ and $Y$ . The PICs lie in the intersection of information and estimation theory, and provide a fine-grained decomposition of the dependence between $X$ and $Y$ . Moreover, the PICs describe which functions of $X$ can or cannot be reliably inferred (in terms of MMSE), given an observation of $Y$ . We demonstrate that the PICs play an important role in information theory, and they can be used to characterize information-theoretic limits of certain estimation problems. In privacy settings, we prove that the PICs are related to the fundamental limits of perfect privacy.

78 citations

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TL;DR: Three basic cooperative models for HSTNs are presented and a survey of the state-of-the-art technologies for each is provided, which contain the main traits of satellite-terrestrial integration but are much simpler and thus more tractable than the whole network.

Abstract: Terrestrial communication networks mainly focus on users in urban areas but have poor coverage performance in harsh environments, such as mountains, deserts, and oceans. Satellites can be exploited to extend the coverage of terrestrial fifth-generation networks. However, satellites are restricted by their high latency and relatively low data rate. Consequently, the integration of terrestrial and satellite components has been widely studied to take advantage of both sides and enable the seamless broadband coverage. Due to the significant differences between satellite communications (SatComs) and terrestrial communications (TerComs) in terms of channel fading, transmission delay, mobility, and coverage performance, the establishment of an efficient hybrid satellite–terrestrial network (HSTN) still faces many challenges. In general, it is difficult to decompose an HSTN into a sum of separate satellite and terrestrial links due to the complicated coupling relationships therein. To uncover the complete picture of HSTNs, we regard the HSTN as a combination of basic cooperative models that contain the main traits of satellite–terrestrial integration but are much simpler and thus more tractable than the large-scale heterogeneous HSTNs. In particular, we present three basic cooperative models, i.e., model ${X}$ , model ${L}$ , and model ${V}$ , and provide a survey of the state-of-the-art technologies for each of them. We discuss future research directions toward establishing a cell-free, hierarchical, decoupled HSTN. We also outline open issues to envision an agile, smart, and secure HSTN for the sixth-generation ubiquitous Internet of Things.

74 citations