rssi | 易学教程

OMNET++: How to obtain wireless signal power?

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问题 I am using the newly released INET 4.0 framework for OMNET++ and I would like to obtain the received signal strength value in a wireless host (of type AdhocHost). How may I do that? 回答1: In INET 4.0.0 the packet received by a module contains several tags. Between others there is SignalPowerInd tag. According to SignalTag.msg: This indication specifies the average analog signal power that was detected during receiving the packet. It may be present on a packet from the phyiscal layer to the

WiFi readings unstable in android

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问题 I am building an application that collects the RSSI levels of APs around me and do some calculations based on that. The problem is that the readings are unstable even if the device is still. For example, signals from an access point fluctuates between -71, -68,-75 and so on.... Is there a way to stabilize the signals? 回答1: In telecommunications, received signal strength indicator (RSSI) is a measurement of the power present in a received radio signal. I think the best you can do is count them

Obtain RSSI with hcidump

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问题 This question was migrated from Raspberry Pi Stack Exchange because it can be answered on Stack Overflow. Migrated 3 years ago . In order to read the raw RSSI values, we use a utility called Hcidump, which monitors the Bluetooth HCI data. Using hcidump commands, we can read the raw RSSI values when an inquiry response message is received. To obtain RSSI values for every response packet we first set the inquiry mode to Inquiry With RSSI.In order to read raw RSSI values we run the hcidump tool

GSM RSSI and LTE RSSI and RSRP

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问题 I am looking to create an app that gets information about the phones connection to the cellular network. My understanding is that RSSI is a measure of cellular signal with GSM and RSRP is a good measure for LTE. To keep it consistent, is it possible to get a RSSI measure for LTE? I am confused about what classes to use to get some of this information. At the moment, I am using the phone state listener which gives me a SignalStrength object. Using this object, I can call the two string method

Application never receives RSSI_CHANGED_ACTION

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问题 I am new to Android programming and am trying to understand the concept of BroadcastReceivers. In order to help myself, I am just trying to write a small application that monitors Wifi signal strength. Now, from my understanding I can simply wait to receive the RSSI_CHANGED_ACTION broadcasted by the system. The RSSI should change frequently which means I should be receiving this notification frequently...however, never do I receive it once. I have watered my code down to the bare minimum so

HC-05 bluetooth RSSI not working with Arduino

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问题 I cannot get my HC-05 bluetooth modules to output RSSI values. I issue it the following commands in series: AT+INIT -> *OK* AT+INQM=1,9,48 -> *OK* AT+INQ -> *No response, it starts flashing rapidly, indicating AT mode is no longer active* After the INQ command, the module it starts flashing rapidly. I think this means it has exited AT command mode, and I get not response on the INQ request. I have to issue the INIT command before the INQM? as otherwise it gives back an error(16). I have even

RadioTap headers in scapy

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I'm trying to send and receive packets with scapy and read the RadioTap Header. The wireless adapter (and driver) is able to handle those headers, but I can't seem to get them. Whenever I send a normal packet in scapy, is does not contain such a header (thus, sniffing packets and checking one with pkt.haslayer(RadioTap) returns "0", and I am not able to display the header like with pkt[RadioTap].show() ). If I explicitely construct my packets with a RadioTap header (like in a pkt = RadioTap() and view it, I can get a RadioTap header, but it is empty. After sending it and receiving it, I can

How does veins calculate RSSI in a Simple Path Loss Model?

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问题 We are working on an application based on Veins framework which needs RSSI value of received signal and the distance between sender and receiver. We referred to the VeReMi project which also calculates RSSI value and sends it to upper level. We compared our simulation result (RSSI vs Distance) with the VeReMi dataset and they look quite different. Can you help us to explain how RSSI is calculated and whether our result is normal? In our application, we obtain the distance and rssi value by

Bluetooth-Low-Energy RSSI changes periodically on Android devices

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问题 I noticed that the signal strength of Bluetooth Low Energy received on Androids is varying in cycles. The graph below represents the RSSI values of one BLE beacon over two minutes. The receiving Android and the beacon were both static with a distance of 1 meter. I made sure that there is as low interference as possible. The Android was a Nexus 5, but I had the same phenomenon with other Android devices, all running on API 21. I could not test it on iOS yet. RSSI Graph You can see that there

ESP32 应用实践：基于混杂接收模式的人流量检测

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前言 ESP32 是一颗低功耗、高集成度、性能稳定的 Wi-Fi /BLE 芯片，是物联网开发的首选设备。它采用 2.4 GHz Wi-Fi 加蓝牙双模芯片，采用 TSMC 低功耗 40nm 技术，功耗性能和射频性能最佳，安全可靠，易于扩展至各种应用。同时集成了双核 160 MHz MCU、两个浮点运算单元 (FPU)、硬件安全加速器、电容触摸传感器、霍尔传感器、ADC、DAC、蓝牙/Wi-Fi 协议栈、TR 滤波器、双工器、功率放大器、接收低噪声放大器、射频 balun 和天线开关。ESP32 的外围器件不超过 10 个，即可实现强大的处理性能、可靠的安全性能，以及 Wi-Fi 和蓝牙功能。可作为独立系统运行应用程序或是主机 MCU 的从设备，通过 SPI / SDIO 或 I2C / UART 接口提供 Wi-Fi 和蓝牙功能。专为移动设备、可穿戴电子产品和物联网应用而设计。该款芯片拥有业内最高水平的低功耗芯片的所有特征，比如精细分辨时钟门控、省电模式和动态电压调整等。集成了更多的元器件，性能稳定，易于制造，工作温度范围达到 -40°C 到 +125°C。ESP32 还集成了先进的自校准电路，实现了动态自动调整，可以消除外部电路的缺陷以及适应外部条件的变化。总之，是一款极其优秀的物联网芯片。混杂模式也称 sniffer, 也称嗅探模式。就是接收所有经过网卡的数据包