You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Survey of Limitations and Enhancements of the IPv6 Routing Protocol for Low-power and Lossy Networks: A Focus on Core Operations 
Chapter Title:  IV. RPL LIMITATIONS AND DRAWBACKS 
1. Abstract of Cited Paper (BIB001):  Routing Protocol for Low Power and Lossy networks (RPL) is the de-facto standard for routing in resource-constrained low-power and lossy networks (LLNs) which represent the building block for the ever-growing Internet of Things (IoT). RPL along with other routing protocols make the deployment of Trickle algorithm as a mechanism for controlling and maintaining the routing traffic frequency. Trickle employs two different techniques to manage the routing traffic efficiently. Firstly, the suppression phase where a node suppresses its control data transmission if it is redundant. Secondly, the traffic frequency adaptation, where the nodes increase their sending rate when discovering inconsistency while slow down their rate as the network becomes stable. The efficiency of Trickle has been approved in terms of power consumption and scalability, however, imposing the so-called listen-only period as a solution for the short-listen problem comes at the expense of increased convergence time. Thus, in this paper, an enhanced version of Trickle is proposed, namely, E-Trickle which solves the short-listen problem without imposing the listen-only period. Simulation results show that E-Trickle have decreased the convergence time by up to 43% while preserving the same efficiency of Trickle in terms of power consumption, scalability and reliability.

Literature Review:
As the de-facto standard for routing in IoT networks, a plethora of recent studies have evaluated RPL performance reporting several limitations and pitfalls that need to be addressed BIB001 - BIB002 . In the next subsections, we elaborate on the key weaknesses and limitations reported in the literature related to RPL's OFs (Section V-A), RPL' downward routing (Section V-B) and RPL's routing maintenance (Section V-C). A summary of these limitations is presented in Table 2 .