Mobile ad hoc networks (MANETs) are critical in the mobile era. There are more and more people using mobile networks, meaning more and more nodes coexist in a MANET. Therefore, designing and evaluating scalable network routing protocols among these mobile nodes becomes extremely critical. This paper provides a survey for the current state of the art of one category of routing protocols in MANETs: distributed hash table-based routing.

The related works and introduction sections are tutorial-like and straightforward. The authors first introduce two different categories of routing protocols for MANETs: flat/hierarchical routing and geographic position-based routing. The authors then introduce the DHT-based routing protocols. In the past few years, distributed hash tables have become a popular underlying mechanism in the design of next-generation networks. Researchers have used DHTs in MANETs to realize more efficient and scalable routing protocols. The introduction part is satisfactory in the sense that it makes this work interesting even for non-experts in the field.

Because the design of DHT-based routing protocols in MANETs is a hot topic, there have already been some evaluations and surveys of it. However, this paper presents the fine-grained classification of DHT-based routing protocols. In each specific DHT-based routing protocol, the authors present detailed information on how the protocol uses DHT. Readers can find almost all of the DHT-based routing protocols for MANETs in the past ten years. The authors are able to summarize the contributions and limitations of each protocol discussed. For example, 3D-RP is “designed to address the mismatch problem” in MANETs. However, it is only “designed for networks with low mobility” because it “does not address the network partitioning and merging problem.”

The organization of the paper is somewhat flawed because section 2 is too long and not well sectioned. All DHT-based protocols are mixed together in a long section without sub-sections, making it hard for readers to read about each protocol clearly.

In summary, this paper is a good survey of the current state of the art. The authors show a good understanding of DHT-based protocols in MANETs, and they are able to comment accurately on the pros and cons of previous work.