Browsing by Author "Pereira, Carlos"
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- Assessing the ESP8266 WiFi module for the Internet of ThingsPublication . Mesquita, João; Guimarães, Diana; Pereira, Carlos; Santos, Frederico; Almeida, LuisThe Internet of Things (IoT) is experiencing rapid growth and being adopted across multiple domains. For example, in industry it supports the connectivity needed to integrate smart machines, components and products in the ongoing Industry 4.0 trend. However, there is a myriad of communication technologies that complicate the needed integration, requiring gateways to connect to the Internet. Conversely, using IEEE 802.11 (WiFi) devices can connect to existing WiFi infrastructures directly and access the Internet with shorter communication delays and lower system cost. However, WiFi is energy consuming, impacting autonomy of the end devices. In this work we characterize a recent WiFi-enabled device, namely the ESP8266 module, that is low cost and branded as ultra-low-power, but whose performance for IoT applications is still undocumented. We explore the built-in sleep modes and we measure the impact of infrastructure parameters beacon interval and DTIM period on energy consumption, as well as packet delivery ratio and received signal strength as a function of distance and module antenna orientation to assert area coverage. The ESP8266 module showed suitability for battery powered IoT applications that allow 2–4 days recharge cycles on a 1000mAh battery with seconds-scale transmission intervals.
- Assessing the ESP8266 WiFi module for the Internet of ThingsPublication . Mesquita, João; Guimarães, Diana; Pereira, Carlos; Santos, Frederico; Almeida, LuisThe Internet of Things (IoT) is experiencing rapid growth and being adopted across multiple domains. For example, in industry it supports the connectivity needed to integrate smart machines, components and products in the ongoing Industry 4.0 trend. However, there is a myriad of communication technologies that complicate the needed integration, requiring gateways to connect to the Internet. Conversely, using IEEE 802.11 (WiFi) devices can connect to existing WiFi infrastructures directly and access the Internet with shorter communication delays and lower system cost. However, WiFi is energy consuming, impacting autonomy of the end devices. In this work we characterize a recent WiFi-enabled device, namely the ESP8266 module, that is low cost and branded as ultra-low-power, but whose performance for IoT applications is still undocumented. We explore the built-in sleep modes and we measure the impact of infrastructure parameters beacon interval and DTIM period on energy consumption, as well as packet delivery ratio and received signal strength as a function of distance and module antenna orientation to assert area coverage. The ESP8266 module showed suitability for battery powered IoT applications that allow 2-4 days recharge cycles on a 1000mAh battery with seconds-scale transmission intervals.
- Feasibility of Gateway-Less IoT E-Health ApplicationsPublication . Pereira, Carlos; Guimarães, Diana; Mesquita, João; Santos, Frederico; Almeida, Luis; Aguiar, AnaMachine-to-Machine (M2M) communications are a key enabler of Internet of Things (IoT) applications. One domain with growing interest in M2M/IoT is e-health, either for self-monitoring, home monitoring, or hospital systems. However, current sensing devices in this domain rely on short-range communication protocols that require a gateway (GW) for Internet connection. Smartphones have been proposed as GWs in mobile M2M communications due to their enhanced connectivity and sensing capabilities. However, the GW functionality impacts on the smartphone usability, causing undesirable battery depletion and the smartphone itself increases the overall cost of e- health solutions. In this work, we propose converging e-health devices and Wi-Fi towards direct Internet access through the existing Wi-Fi infrastructure and by-passing current GWs. We use recent low-cost ultra low-power Wi-Fi modules and feature them with M2M capabilities supporting their integration in an interoperable e-health framework. We present results on end-to-end latency and power requirements within a concrete e-health use case that show the feasibility of the proposed GW-less solution.