| # | Project Topics | Teams | Date |
|---|
| | Bits & Packets | | |
| 1 | What is code combining, how/why does it work? Illustrate its use in the context of Hybrid ARQ systems, and identify its benefits and disadvantages in that context. | | |
| 2 | What is MP3, how/why does it work, where is it used, what are its benefits and disadvantages? | Parastoo Fotoohi and Alline Kabbatende | 11/10/11 |
| 3 | How does Lempel-Ziv compression work and what are its main advantages over other compression techniques? What differences exist between its several versions? Identify other approaches that can provide a better compression ratio, and highlight their respective advantages and disadvantages compared to Lempel-Ziv techniques.? | Dhruv Bolakani and Swarupa Parayil | 10/27/11 |
| 4 | What is a Reed-Solomon code, how/why does it work, where is it used, what are its benefits and disadvantages? | Minesh Zota and Nitish Malhotra | 11/03/11 |
| 5 | What are turbo codes, what is their main difference with earlier codes and how do they work? Where are they used, what are their benefits and disadvantages? | Kavita Kamesh and Bhumika Malik | 11/03/11 |
| 6 | When is forward error correction better than retransmission? Define your own metric to measure “better”, and identify scenarios that highlight the pros and cons of each option.? | Lei Lu and Yifei Zhou | 11/10/11 |
| 7 | What are packet-level diversity codes and where is their usage potentially useful? Why are they not widely in use today and what might be scenarios that would change this? | | |
| 8 | Discuss the use of using Cyclic Redundancy Codes (CRC) to perform packet framing. How and why does it work and what is needed in order to ensure robust operation, e.g., resilient to bit errors. Discuss and explain the scheme’s with both fixed and variable length packets. | Partially covered in class | |
| 9 | What are scramblers and line codes? What do they have in common and how do they differ? What are their main purposes and in what settings are they used. Identify environments where they are not needed and explain why. | | |
| 10 | What is Network Coding, how/why does it work, where is it used, what are its benefits and disadvantages/limitations? | Tianshi Zhu and Zhihong Yi | 11/03/11 |
| | Links, Switches, & QoS Mechanisms | | |
| 11 | What is a broadcast storm, where, why and how does it arise, and what are its consequences? What are mechanisms to prevent it or mitigate its impact? | Jing Liu and Yi Yang | 11/10/11 |
| 12 | Consider a simple crossbar switch with N inputs and N outputs. What can you say about its performance, e.g., the maximum load that is feasible on the input links under different traffic distributions? Provide a comprehensive discussion of this type of switch, their performance, and how to improve them. | | |
| 13 | What is a network processor and what are its main functions? Where is it used and what are alternative technologies? What are some its main features and what are the challenges involved in designing network processors? | | |
| 14 | Discuss the operation of an inverse multiplexer, how/why does it work, where is it used, what are its benefits and disadvantages? | | |
| 15 | Investigate and quantify the impact of channels of different quality (supporting different bit rates) on the operation of an 802.11 system. In particular, how is the “goodput” of high-rate channels (between users and the access point) affected by the presence of low-rate channels? How big is the effect, when does it arise, how could it be mitigated, e.g., by modifying the protocol? | | |
| 16 | What is Deficit-Round-Robin (DDR), how/why does it work, where is it used, what are its benefits and disadvantages? What alternative approaches exist and how to they compare to DDR? | | |
| 17 | What is Random Early Discard and why was it suggested in the first place? Is it widely used today, and if not what can this be attributed to? Irrespective of the actual use of RED, discuss what subsequent investigations and technologies it has given rise to. | | |
| 18 | Investigate the operation of buffer insertion rings as a solution for local/metropolitan area networks. What are their main benefits and conversely what challenges are involved in making them suitable to handling a broad range of traffic patterns. | | |
| 19 | Discuss differences and similarities between CDMA, FDMA and TDMA channel access techniques, and for each identify both its main advantages and the main technical hurdles it introduces. Expand on the use of CDMA and TDMA techniques in the context of cellular systems, and highlight the pros and cons of each approach in this setting. What do you think this implies for the future of wireless cellular technology? | Jin Xinwei and Qin Ye | 11/17/11 |
| 20 | What is WiMax and what are its main technical components, and in particular how does it differ from existing popular wireless access technologies, e.g., WiFi? What are is possible uses and what are its competitors for those uses? Why should it win or lose the competition for deployments? | Indira Kassymkhanova and Lei Yao | 11/17/11 |
| 21 | Compare the various technical solutions currently vying to contenders for 4G solutions, e.g., WiMax and LTE, where they differ technologically speaking, to what extent are they truly "single" standards (are there several "versions" of each, e.g., in different countries), and what are the pros and cons that may have motivated their selection and deployment by different companies (the latter being not always solely a function of technology). | Ogugua Chioke and Kevin Jiang | 11/17/11 |
| 22 | What is rate-based flow control and how does it differ from traditional window-based flow control mechanisms as used in, say, TCP. Where has rate-based flow control been used and what are its benefits. Compare rate and window-based flow control schemes in terms of both performance and complexity. | | |
| | Network Protocols & Mechanisms | | |
| 23 | What are Distributed Hash Tables, how do they work, where are they used, what are their benefits and disadvantages? Discuss examples of recent systems for which they have been proposed and why. | Narendra Subbanarasimhaiah Shashidhara and Lohit Sarna | 11/17/11 |
| 24 | Discuss the Patricia trie implementation of IP forwarding in Unix, how/why does it work (it was chosen as the implementation of choice), what are its benefits and disadvantages over other alternatives, and to what extent is it still in use or not in modern routers in the Internet (why/why not)? | | |
| 25 | What are routing loops, when and why do they arise, and what is their impact on network performance? What protocols exist, if any, which “guarantee” the complete avoidance of routing loops at all times, and what are the costs of the underlying loop-avoidance mechanisms? | Yunlong Mou and Cuifan Yang | 12/01/11 |
| 26 | What is Constrained Shortest Path First (CSPF) routing, how does it work, where is it used and for what purpose, what are its benefits and disadvantages compared to other routing schemes? | | |
| 27 | What is route flap dampening, how does it work, where is it used and for what purpose, what are its benefits and disadvantages and in particular its impact on network stability and the ability to quickly recover from failures? | | |
| 28 | What are the major differences between the OSPF and IS-IS protocols and do they have implications regarding the expected future usage of the two protocols? | | |
| 29 | Discuss the operation of the Virtual Router Redundancy Protocol, and identify when and why it is used and what overhead it imposes to ensure it is properly configured. Are there any meaningful functional differences between this protocol and Cisco’s proprietary Hot Standby Router Protocol? Justify your answer either way. | Swaraj Chhatre and Chinmay Gupte | 12/01/11 |
| 30 | What are the challenges faced by traditional routing protocols when contemplating using them in mobile ad hoc networks, and why is their use without modifications unlikely to be effective? Describe current proposals, including modifications to existing routing protocols, to offer routing capability in mobile ad hoc networks. | | |
| 31 | The Internet suite of routing protocols combines the notion of addressing and location, i.e., your IP address also determines your location on the Internet. Identify potential shortcomings of that design and discuss possible alternatives to overcome them, including relevant standardization efforts if any. | | |
| 32 | What is Anycast DNS? How does it work, what problem(s) is it meant to solve and what are its benefits? How does it compare to alternatives? Has it been deployed, and if yes what are its costs? | | |
| 33 | The need for IPv6 was first conceived over 15 years ago, but it has not (yet) seen much deployment. Why is that (identify some of the main reasons and/or alternatives) and what are the main obstacles that confront the migration from the current IPv4 Internet to an IPv6 one? Are there signs of changes, and whether yes or no, why? | Abhay Amin and Shlok Vaidya | 10/27/11 |
| | Applications & End-to-End Issues | | |
| 34 | What is TCP FAST, how does it work, where is it used and for what purpose, what are its benefits and disadvantages compared to other versions of TCP? | Priyankan Choudhury and Tushar Savant | 11/10/11 |
| 35 | What are the differences between MPEG2 and MPEG4 and how do they translate into different benefits in terms of video quality and bit rates? Are there disadvantages when comparing the two standards and if yes, what are they? | Qing Li and Bo Pan | 11/10/11 |
| 36 | How does the SSL protocol work, why is it viewed as secure and on what assumptions does that security rely? Are there potential (future) vulnerabilities to SSL as technology evolves? What alternatives might be available if one wanted/needed to replace SSL? | Raghav Ravi and Tirumalai Sundararam | 12/01/11 |
| 37 | How does VoIP work and how is it different from traditional telephony? Identify key technical differences and the technologies involved in enabling voice communication over an IP network. Use the example of Skype to illustrate interactions between two VoIP terminals as well as how it is possible for them to communicate with standard telephones. In the latter case, identify the technical challenges involved. | Chen Ma and Hang Lu | 10/27/11 |
| 38 | What are Content Distribution Networks (CDN), how do they work, where are they used and for what purpose, what are their benefits and what are the challenges involved in making them efficient? | Bo Tang and Huang Yu | 11/17/11 |
| 39 | What are Access Control Lists (ACL), where are they used for, and how do they work? More generally, discuss the functionality offered by firewalls and the trade-off between security and impact on applications that they entail. | Wenpeng Jia and me Chenyan Sun | 12/01/11 |
| 40 | What are NATs and PATs and how do they work? What problems are they meant to solve and conversely what complexity do they introduce in both network and application operations? | | |
| 41 | Discuss metrics used to measure the quality of VoIP and explain their differences with quality metrics used for voice transmission over the traditional phone network. In other words, what performance parameters do the new metrics need to capture and why, and how are these then mapped into subjective voice quality? | Gaurav Mallawat and Rushabh Warhadkar | 10/27/11 |
| 42 | One of the main problems in peer-to-peer (p2p) systems is dealing with free-loaders that do not contribute to disseminating information. What techniques free and commercial p2p systems have been investigating for dealing with this issue? Provide explicit examples of actual systems and the mechanisms they use, and discuss the pros and cons of those approaches as well as their (expected) effectiveness. | Runyu Ma and Ying Zheng | 11/03/11 |
| 43 | How do SPAM filters work and how is their performance measured? What are the basic technologies used to identify SPAM and how do they work? Where are SPAM filters deployed and what effect have they had on SPAM volume on one hand and email usage on the other? Why is it difficult to identify the origin of SPAM mail? | Nirmiti Mantri and Meng Zhang | 11/03/11 |
