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: Multimedia Internet of Things: A Comprehensive Survey 
Chapter Title:  3) APPLICATION LAYER 
1. Abstract of Cited Paper (BIB001):  This paper provides an overview of the Internet of Things (IoT) with emphasis on enabling technologies, protocols, and application issues. The IoT is enabled by the latest developments in RFID, smart sensors, communication technologies, and Internet protocols. The basic premise is to have smart sensors collaborate directly without human involvement to deliver a new class of applications. The current revolution in Internet, mobile, and machine-to-machine (M2M) technologies can be seen as the first phase of the IoT. In the coming years, the IoT is expected to bridge diverse technologies to enable new applications by connecting physical objects together in support of intelligent decision making. This paper starts by providing a horizontal overview of the IoT. Then, we give an overview of some technical details that pertain to the IoT enabling technologies, protocols, and applications. Compared to other survey papers in the field, our objective is to provide a more thorough summary of the most relevant protocols and application issues to enable researchers and application developers to get up to speed quickly on how the different protocols fit together to deliver desired functionalities without having to go through RFCs and the standards specifications. We also provide an overview of some of the key IoT challenges presented in the recent literature and provide a summary of related research work. Moreover, we explore the relation between the IoT and other emerging technologies including big data analytics and cloud and fog computing. We also present the need for better horizontal integration among IoT services. Finally, we present detailed service use-cases to illustrate how the different protocols presented in the paper fit together to deliver desired IoT services.

Literature Review:
It is the top layer in IoT architecture, also known as the business layer BIB002 . Based on the functionality of the layer, it is virtually subdivided into two layers, i.e., service sublayer and application sublayer BIB001 . The service sublayer provides information management, data mining, data analytics, and decision-making services. The application sub-layer needs to provide the required services to end-user or machines. The application layer primarily analyzes the required services of IoT application and transforms the physical world data into the expressions of cyber world demands. Constrained Application Protocol (CoAP) is proposed by IEEE 802.15.4 standard  to improve data packets delivery and to reduce overheads. The messaging layer and request/response layer are two defined layers in CoAP. Other proposed IoT application layer protocols are Data Distribution Service (DDS), Advanced Message Queue Protocol (AMQP), and Extensible Messaging and Presence Protocol (XMPP) BIB002 .