Recent technologies have made the life of people more comfortable and more straightforward than it was before. With the development of information technology, the Internet of Things (IoT) as an emerging technology has been entered into a lane of development. With the advent of IoT, data sharing, and connections among systems, devices, and people have been facilitated, and daily devices have been equipped with sensors and applications to provide their functionality through services. As a matter of fact, IoT provides a platform where everyday objects become smarter than before, everyday communication becomes informative, and everyday processes become intelligent. In this regard, to provide novel IoT services, numerous heterogeneous frameworks and protocols have been proposed. Since the number of IoT devices or objects is growing day by day, and the number of services is also increasing, discovering and locating appropriate services becomes a vital challenge, and the traditional service discovery strategies are not efficient enough to handle this issue. Service discovery refers to the process of finding suitable services according to clients' requests. Although the service discovery problem has essential impacts on the IoT, there is not any detailed and systematic study of the existing methods in this field. Therefore, this paper aims to find, categorize, and investigate all the effective and valid papers in the field of service discovery in the IoT using a systematic method. The selected papers are discussed based on various service discovery metrics and other criteria such as adopted architecture, search method, service description, discovery scope, adopted simulation tools, and datasets. The advantages and weaknesses of each reviewed paper are specified. Moreover, an abreast comparison of the selected papers is presented, in which the aforementioned methods are evaluated considering the mentioned metrics and criteria. Finally, future research directions and challenging problems are outlined to help researchers improve their innovations.

最新技术使人们的生活比以前更舒适，更直接。随着信息技术的发展，物联网（IoT）作为一种新兴技术已经进入了发展道路。随着物联网的出现，数据共享以及系统，设备和人员之间的连接变得更加便利，并且日常设备都配备了传感器和应用程序，以通过服务提供其功能。实际上，物联网提供了一个平台，在该平台上，日常对象变得比以前更智能，日常通信变得信息丰富，日常流程变得智能。在这方面，为了提供新颖的物联网服务，已经提出了许多异构框架和协议。由于物联网设备或对象的数量每天都在增长，并且服务的数量也在增加，发现和定位合适的服务成为一个严峻的挑战，而传统的服务发现策略还不足以解决这个问题。服务发现是指根据客户的请求找到合适的服务的过程。尽管服务发现问题对物联网具有至关重要的影响，但是对该领域中的现有方法尚无任何详细而系统的研究。因此，本文旨在通过系统的方法来查找，分类和研究IoT服务发现领域中的所有有效和有效论文。根据各种服务发现指标和其他标准（如采用的体系结构，搜索方法，服务描述，发现范围，采用的仿真工具，和数据集。指出了每篇评论文章的优缺点。此外，提出了对所选论文的最新比较，其中考虑了上述指标和标准对上述方法进行了评估。最后，概述了未来的研究方向和具有挑战性的问题，以帮助研究人员改善其创新能力。