# IoT-Based Solid Waste Management Solutions: A Survey
## 5 Value Chain of IoT-Based Waste Management Systems
Wi-Fi uses radio waves for communication within a range of 100 m and allows devices to communicate through an ad hoc configuration [63], i.e., without the use of a router. Bluetooth is a communication technology widely used for communication between devices at a short distance. It uses basic radio waves with short wavelengths to guarantee a saving in the consumption of batteries [64]. 802.15.4, developed by the IEEE, provides specifications in low power wireless networks for both the physical layer and the medium access control layer by promoting reliable and scalable communication [73]. Long term evolution (LTE) is a wireless communication standard that enables high speed data transfer between mobile phones based on GSM/UMTS network technologies and encompasses devices in locomotion at high speeds in  
Figure 3: Illustration of a value chain for IoT-based waste management systems. addition to providing multicast-based services and broadcast [66]. LTE Advanced (LTE-A) is an enhanced version of conventional LTE and includes broadband coverage, spatial multiplexing, greater coverage, and better performance with lower latencies [67]. Better known as the fourth generation of mobile communications is an evolution of WCDMA (3G) and GSM/GPSR (2G). * **Computation. ** It is the unit that represents the computational capacity of IoT, based on software and applications. There is a huge range of hardware development platforms for IoT application operation; some examples are: Arduino [74], UDOO [75], FriendlyARM [76], Intel Galileo [77], Raspberry PI [78], Gadgeteer [79], Beagle Bone [80], Cubieboard [81], Z1 [82], WiSense [83], Mulle [84], and T-Mote Sky [85], but operating systems are seen as vital because they run throughout the entire system execution period. In addition to TinyOS [86], LiteOS [87], and RiotOS [88], which also offer a lightweight operating system, it is possible to cite the Contiki RTOS, widely used in IoT scenarios [89; 90] for IoT environments. Cloud platforms are another important computing component within an IoT solution. These platforms provide capabilities for receiving data from intelligent objects to be processed or stored, so that in the future, users can benefit from the knowledge of the extracted data. Data analysis platforms within IoT are crucial due to the specific characteristics of this type of solutions given heterogeneous data and systems integration. Similarly, IoT-based solid waste management works with real time data that require correlation and sharing. To meet these requirements in a system with a large volume of connected devices generating data by different flows, it is increasingly necessary to adopt cloud computing where storage, processing, and connection capacity are needed according to the growing demand for data analysis. * **Services. ** Within IoT, services can be classified through four classes: Services related to identity that represents the most basic and essential to other services--applications that need to take objects from the real world to the virtual must first identify them; information aggregation services responsible for summarizing the raw information that needs to be processed and exposed to the applications; collaborative-aware services acting on aggregation services in decision making; and ubiquitous services, providing support services. * **Semantics. ** Semantics refers to the ability to extract knowledge in an intelligent way, but through other possibilities and in the proportion in which the services require [91]. This extraction of knowledge covers the discovery and use of modeling resources and information and includes the recognition and analysis of the data so that it makes sense for the right decision by providing the exact service. Semantics behaves like the brain of IoT, sending demands to the specific resource. Such requirements are supported by semantic web technologies, such as the resource description framework (RDF), OWL (web ontology language), and EXI (efficient XML interchange).