CRAWDAD mannheim/compass (v. 2008-04-11)

Traces of signal strength of 802.11 APs for the COMPASS positioning system.Note: This dataset has multiple versions. The dataset file names of the data associated with this version are listed below, under the 'Traceset' heading and can be downloaded under 'Dataset Files' on the right-hand side of the page.COMPASS is a positioning system based on 802.11 and digital compasses. We apply an two-stage fingerprinting approach: In the training phase, we sample the signal strength of neighboring access points for selected orientations at each reference point and store the data in a database. During the positioning phase, the orientation of the user is utilized to preselect a subset of the training data and based on this data compute her position.last modified :2008-04-16release date :2008-04-11date/time of measurement start :2006-02-11date/time of measurement end :2006-10-14collection environment :Positioning systems are one of the key elements required by location-based services. We design and implement a positioning system called COMPASS which is based on 802.11-compliant network infrastructure and digital compasses. On the mobile device, COMPASS samples the signal strength values of different access points in its communication range and utilizes the orientation of the user to preselect a subset of the training data. The remaining training data is used by a probabilistic positioning algorithm to determine the position of the user. While prior systems show limited accuracy due to blocking effects caused by the human body, we apply digital compasses to detect the orientations of the users so that they can deal with these blocking effects. After a short period of training the COMPASS system achieves an average error distance of less than 1.65 meters in the experimental environment of 312 square meters.network configuration :The test environment is equipped with five Linksys / Cisco WRT54GS and four Lancom L-54g access points. All access points support 802.11b and 802.11g. One Lancom and all Linksys access points are located on the same floor as our testing area whereas three Lancom access point are located in other places inside the building. The exact position of the access points located inside the testing area is marked by squares in the floor plan (see the download link below).data collection methodology :We deployed our positioning system in the hallway of an office building on the campus of the University of Mannheim. The operation area is nearly 15 meters in width and 36 meters in length, covering an area of approximately 312 square meters. The floor plan of the testing area is shown in the floor plan figure (see the download link below). The large hallway in the left part of the map is connected by two narrow hallways that are separated by rooms such as archives and a kitchen. We marked the floor plan (see the download link below) with markers depicting the grid of the reference points (light-colored dots) and the online measurement points (dark dots). The access points are marked by squares. As a client, we used a Lucent Orinco Silver PCMCIA network card supporting 802.11b. We collected the signal strength samples on an IBMThinkpad R51 running Linux kernel 2.6.13 and Wireless Tools 28pre. To obtain the orientation of the user we used the Silicon Laboratories C8051F350 Digital Compass Reference Design Board. This device provides a USB-to-Serial bridge to access the data and is powered by the USB electricity supply. We calibrated the compass in the middle of the operation area. In a closer area around the calibration point we measured a variation of 1 degree. However, variations up to 23 degree were rarely detected at a few points of the testing area. These measurement errors occured always close to electromagnetic objects such as high-voltage power lines and electronic devices.Tracesetmannheim/compass/signalstrengthA traceset of signal strength collected from 802.11 APs for the COMPASS positioning system.files: offline.tar.gz, online.tar.gzdescription: A traceset of signal strength collected from 802.11 APs for the location estimation used by the COMPASS positioning system.measurement purpose: Location-aware Computing, Positioning Systemsmethodology: The grid of reference points applied to the operation area includes 166 points with a spacing of 1 meter (see the light-colored dots in the floorplan figure). During the offline phase, the signal strength was measured at reference points for different orientations. We then randomly selected 60 coordinates and orientations for the online phase.last modified: 2006-11-14dataname: mannheim/compass/signalstrengthversion: 20060913change: the initial versionrelease date: 2006-09-13date/time of measurement start: 2006-02-11date/time of measurement end: 2006-03-09mannheim/compass/signalstrength Tracesoffline: A trace of signal strength values from 802.11 APs measured at reference points for different orientations.configuration: During the offline phase, the signal strength was measured at reference points for different orientations. We collected 110 signal strength measurements at each reference point and for each orientation. This leads to 146,080 measurements for the offline phase. We spent over 10 hours to collect all the data.format: (format of trace data)t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength values from 802.11 APs measured at reference points for different orientations for the offline phase of the COMPASS positioning system.last modified: 2006-11-14dataname: mannheim/compass/signalstrength/offlineversion: 20060913change: the initial versionrelease date: 2006-09-13date/time of measurement start: 2006-02-11date/time of measurement end: 2006-03-09url: /download/mannheim/compass/offline.tar.gzonline: A trace of signal strength, which is derived from mannheim/compass/signalstrength/offline.configuration: We randomly selected 60 coordinates and orientations for the online phase. The only condition to select a point inside the testing area as an online set point is that it is surrounded by four reference points. Again, we collected 110 signal strength measurements for each online set point, leading to 6,600 measurements in total.format: (format of trace data) t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength, which is derived from mannheim/compass/signalstrength/offline for online phase of the COMPASS positioning system.last modified: 2006-11-14dataname: mannheim/compass/signalstrength/onlineversion: 20060913change: the initial versionrelease date: 2006-09-29date/time of measurement start: 2006-02-11date/time of measurement end: 2006-03-09url: /download/mannheim/compass/online.tar.gzmannheim/compass/802.11A traceset of signal strength collected from 802.11 APs for the COMPASS positioning system.description: A traceset of signal strength collected from 802.11 APs for the location estimation used by the COMPASS positioning system.measurement purpose: Location-aware Computing, Positioning Systemsmethodology: 1. Local Test Environment We deployed the positioning system on the second floor of an office building on the campus of the University of Mannheim. The operation area is nearly 15 meters in width and 36 meters in length, covering an area of approximately 312 square meters. The floor plan of the operation area is shown in [Figure: floor plan for mannheim/compass/802.11]. The large hallway in the left part of the map is connected by two narrow hallways that are separated by rooms such as a copier room, an archive and a kitchen. The rooms depicted on both sides of the narrow hallways are mainly used as offices, and due to access restrictions they could not be included into the operation area. 2. Hardware and Software Setup Initially, the test environment was covered by one Linksys / Cisco WRT54GS and two enterasys RBT-4102-EU access points administered by the computer center of our university. We additionally installed 11 access points: Two D-Link DWL-G700AP, three NETGEAR WG102, and six Linksys / Cisco WRT54G access points. All access points support 802.11b and 802.11g. Except of one enterasys access point, all access points are located on the same floor as our operation area. This particular enterasys access point is placed on a lower floor, however, it covers the operation area completely. The position of this access point is marked by an orange ring and the positions of the other access points are marked by orange circles (see [Figure: floor plan for mannheim/compass/802.11]). As a client, we used a Lucent Orinoco Silver PCMCIA network card supporting 802.11b. This card was plugged into an IBM Thinkpad R51 running Linux kernel 2.6.13 and Wireless Tools 28pre. To collect signal strength samples, we implemented a framework that contains two parts: A library that cooperates with the network card driver to perform scans and capture internal driver information, and an easy-to-use application that stores these information in a file together with additional data such as the physical position and a timestamp. Further, the application configures the library to select a scan frequency and scan technique for the signal strength measurements. For our experiments we used active scanning. Active scanning is defined in the 802.11 standard1 and it is a technique to find a suitable gateway to the Internet by measuring the signal strength of access points within communication range. From the driver our library collects the following information for each device that replies to an active scan: - MAC address of the device - received signal strength - noise level - mode of the device (i.e. access point or ad-hoc) - frequency used for the communication Although only the MAC address, mode and received signal strength values are required by 802.11-based positioning systems, we stored the additional information for further analysis and debugging purposes.last modified: 2008-05-15dataname: mannheim/compass/802.11version: 20080411change: the initial versionrelease date: 2008-04-11date/time of measurement start: 2006-10-14date/time of measurement end: 2006-10-14mannheim/compass/802.11 Tracesoffline: A trace of signal strength values from 802.11 APs measured at reference points for different orientations.configuration: The grid of reference points applied to the operation area includes 612 points with a spacing of 0.5 meter (see the blue markers in [Figure: floor plan for mannheim/compass/802.11]). During the offline phase, we collected 110 signal strength samples at each reference point, resulting in 72,600 samples in total. We spent over ten hours to collect all the data, however, we want to point out that for a productive deployment of a positioning system 20 signal strength samples and a grid with grid spacing of 1.5 meters will be sufficient, cutting down the expenditure of time to less than half an hour.format:t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength values from 802.11 APs measured at reference points for different orientations for the offline phase of the COMPASS positioning system.last modified: 2008-05-15dataname: mannheim/compass/802.11/offlineversion: 20080411release date: 2008-04-11date/time of measurement start: 2006-10-14date/time of measurement end: 2006-10-14online: A trace of signal strength, which is derived from mannheim/compass/802.11/offline.configuration: For the online phase, we randomly selected 83 coordinates. The only condition to select a point inside the operation area as a online point is that it is surrounded by four reference points of the grid. Again, we collected 110 signal strength samples for each online point, leading to 9,460 samples in total. In [Figure: floor plan for mannheim/compass/802.11] the online points are marked by purple dots.format:t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength, which is derived from mannheim/compass/802.11/offline for online phase of the COMPASS positioning system.last modified: 2008-05-15dataname: mannheim/compass/802.11/onlineversion: 20080411change: the initial versionrelease date: 2008-04-11date/time of measurement start: 2006-10-14date/time of measurement end: 2006-10-14mannheim/compass/fingerprintA traceset of signal strength collected from 802.11 APs for the COMPASS positioning systemdescription: A traceset of signal strength collected from 802.11 APs for the location estimation used by the COMPASS positioning system.measurement purpose: Location-aware Computing, Positioning Systemsmethodology: 1. Local Test Environment We deployed our 802.11-based positioning system on the second floor of our office building on the campus of the University of Mannheim. The operation area is nearly 57 meters in width and 32 meters in length; approximately 221 square meters are covered. The floor plan of the operation area is shown in [Figure: floor plan for mannheim/compass/fingerprint]. 2. Hardware and Software Setup Initially, the test environment was covered by twelve access points. Seven of them are administered by the computer center of our university. The other five are installed in nearby buildings and offices. We additionally installed thirteen access points. Our data show that most of the access points cover only parts of the operation area. In fact, only two access points cover the operation area completely. One of these access points is the one marked in the middle of the storage room in the horizontal hallway in the right part of the building. This access point is located in a suspended ceiling on top of this room. The position of the second access point is in an office one floor below our operation area. The positions of the access points that are located on the same floor and inside the same building parts as our operation area are marked by orange circles in [Figure: floor plan for mannheim/compass/fingerprint]. As a client, we used a Lucent Orinoco Silver PCMCIA network card supporting 802.11b. This card was plugged into an IBM Thinkpad R51 running Linux kernel 2.6.13 and Wireless Tools 28pre. To collect signal strength samples, we implemented our own set of tools called "Loc{lib,trace,eva,ana}".last modified: 2008-05-15dataname: mannheim/compass/fingerprintversion: 20080411change: the initial versionrelease date: 2008-04-11date/time of measurement start: 2006-08-24date/time of measurement end: 2006-08-24mannheim/compass/fingerprint Tracesoffline: A trace of signal strength values from 802.11 APs measured at reference points for different orientations.configuration: The grid of reference spots in the operation area includes 130 spots with a spacing of 1.5 meters (see the blue marks in [Figure: floor plan for mannheim/compass/fingerprint]). During the training phase, we collected 110 signal strength samples at each reference spot.format:t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength values from 802.11 APs measured at reference points for different orientations for the offline phase of the COMPASS positioning system.last modified: 2008-05-15dataname: mannheim/compass/fingerprint/offlineversion: 20080411change: the initial versionrelease date: 2008-04-11date/time of measurement start: 2006-08-24date/time of measurement end: 2006-08-24online: A trace of signal strength, which is derived from mannheim/compass/fingerprint/offline.configuration: For the position determination phase, we randomly selected 46 spots. Again, we collected 110 signal strength samples for each positioning spot. In [Figure: floor plan for mannheim/compass/fingerprint], the positioning spots are marked by purple dots. We spent more than ten hours to collect all the data.format:t="Timestamp"; id="MACofScanDevice"; pos="RealPosition"; degree="orientation"; "MACofResponse1"="SignalStrengthValue","Frequency","Mode"; ... "MACofResponseN"="SignalStrengthValue","Frequency","Mode" t: timestamp in milliseconds since midnight, January 1, 1970 UTC id: MAC address of the scanning device pos: the physical coordinate of the scanning device degree: orientation of the user carrying the scanning device in degrees MAC: MAC address of a responding peer (e.g. an access point or a device in adhoc mode) with the corresponding values for signal strength in dBm, the channel frequency and its mode (access point = 3, device in adhoc mode = 1)description: A trace of signal strength, which is derived from mannheim/compass/fingerprint/offline for online phase of the COMPASS positioning system.last modified: 2008-05-15dataname: mannheim/compass/fingerprint/onlineversion: 20080411change: the initial versionrelease date: 2008-04-11date/time of measurement start: 2006-08-24date/time of measurement end: 2006-08-24

802.11 无线接入点信号强度轨迹，用于 COMPASS 定位系统。注：该数据集存在多个版本。本版本相关的数据集文件名如下，列于 'Traceset' 部分，并可在页面右侧的 'Dataset Files' 下下载。COMPASS 是一种基于 802.11 和数字罗盘的定位系统。我们采用两阶段指纹识别方法：在训练阶段，在每个参考点处对选定方向邻近接入点的信号强度进行采样，并将数据存储在数据库中。在定位阶段，利用用户的朝向预先选择训练数据的一个子集，并基于此数据计算其位置。最后修改日期：2008-04-16发布日期：2008-04-11测量开始日期/时间：2006-02-11测量结束日期/时间：2006-10-14收集环境：定位系统是位置相关服务所需的关键元素之一。我们设计和实现了名为 COMPASS 的定位系统，该系统基于符合 802.11 标准的网络基础设施和数字罗盘。在移动设备上，COMPASS 采样其通信范围内不同接入点的信号强度值，并利用用户的朝向预先选择训练数据的一个子集。剩余的训练数据由概率定位算法用于确定用户的位置。由于人体遮挡效应的限制，先前系统显示出有限的准确性，而我们采用数字罗盘来检测用户的朝向，以便处理这些遮挡效应。经过短暂的训练后，COMPASS 系统在约 312 平方米的实验环境中实现了平均误差距离小于 1.65 米。网络配置：测试环境配备有五台 Linksys / Cisco WRT54GS 和四台 Lancom L-54g 接入点。所有接入点都支持 802.11b 和 802.11g。一个 Lancom 和所有 Linksys 接入点位于我们的测试区域同一楼层，而三个 Lancom 接入点位于建筑内部的其他地方。测试区域内部接入点的确切位置由平面图中的方框标记（见下方的下载链接）。数据收集方法：我们在曼海姆大学校园内一栋办公楼的长廊中部署了我们的定位系统。操作区域宽度约为 15 米，长度约为 36 米，覆盖约 312 平方米的面积。测试区域的平面图显示在平面图图中（见下方的下载链接）。地图左侧的大走廊通过两个狭窄的走廊与房间（如档案室和厨房）隔开。窄走廊两侧的房间主要用作办公室，由于访问限制，它们无法包含在操作区域内。作为客户端，我们使用了一块 Lucent Orinco Silver PCMCIA 网络卡，该卡支持 802.11b。该卡插入到运行 Linux 内核 2.6.13 和 Wireless Tools 28pre 的 IBM Thinkpad R51 中。为了获取用户的朝向，我们使用了 Silicon Laboratories C8051F350 数字罗盘参考设计板。该设备提供 USB 到串行桥接以访问数据，并由 USB 电源供电。我们在操作区域的中间对罗盘进行了校准。在靠近校准点的更小区域内，我们测量到 1 度的变化。然而，在测试区域的几个点上，很少检测到 23 度的变化。这些测量误差总是在电磁物体（如高压电线和电子设备）附近发生。Tracesetmannheim/compass/signalstrength从 802.11 无线接入点收集的信号强度轨迹，用于 COMPASS 定位系统。文件：offline.tar.gz, online.tar.gz描述：从 802.11 无线接入点收集的信号强度轨迹，用于 COMPASS 定位系统中的位置估计。测量目的：位置感知计算，定位系统。方法：1. 本地测试环境我们在曼海姆大学校园内一栋办公楼二楼部署了我们的定位系统。操作区域宽度约为 15 米，长度约为 36 米，覆盖约 221 平方米的面积。操作区域的平面图显示在 [图：mannheim/compass/802.11 的平面图]。地图左侧的大走廊通过两个狭窄的走廊与房间（如复印室、档案室和厨房）隔开。窄走廊两侧的房间主要用作办公室，由于访问限制，它们无法包含在操作区域内。2. 硬件和软件设置最初，测试环境由一个 Linksys / Cisco WRT54GS 和两个由我们大学计算机中心管理的 enterasys RBT-4102-EU 接入点覆盖。我们另外安装了 11 个接入点：两个 D-Link DWL-G700AP、三个 NETGEAR WG102 和六个 Linksys / Cisco WRT54G 接入点。所有接入点都支持 802.11b 和 802.11g。除了一个 enterasys 接入点外，所有接入点都位于我们的操作区域同一楼层。这个特定的 enterasys 接入点位于一个较低的楼层，但它完全覆盖了操作区域。该接入点的位置由橙色环标记，而其他接入点的位置由橙色圆圈标记（见 [图：mannheim/compass/802.11]）。作为客户端，我们使用了一块 Lucent Orinoco Silver PCMCIA 网络卡，该卡支持 802.11b。该卡插入到运行 Linux 内核 2.6.13 和 Wireless Tools 28pre 的 IBM Thinkpad R51 中。为了收集信号强度样本，我们实现了一个框架，该框架包含两个部分：一个库，与网络卡驱动程序协同工作以执行扫描并捕获内部驱动程序信息；以及一个易于使用的应用程序，将信息存储在文件中，并附带其他数据，如物理位置和时间戳。此外，应用程序配置库以选择扫描频率和扫描技术进行信号强度测量。在我们的实验中，我们使用了主动扫描。主动扫描在 802.11 标准中定义，是一种通过测量通信范围内接入点的信号强度来查找合适网关的技术。从驱动程序中，我们的库收集了以下信息：- 设备的 MAC 地址- 接收到的信号强度- 噪声水平- 设备的模式（即接入点或 ad-hoc）- 用于通信的频率尽管只有 MAC 地址、模式和接收到的信号强度值对于基于 802.11 的定位系统是必需的，但我们存储了其他信息，用于进一步分析和调试。最后修改日期：2008-05-15数据名称：mannheim/compass/802.11版本：20080411变更：初始版本发布日期：2008-04-11测量开始日期/时间：2006-10-14测量结束日期/时间：2006-10-14mannheim/compass/802.11 Tracesoffline：在参考点处针对不同方向测量的 802.11 无线接入点信号强度值轨迹。配置：应用于操作区域的参考点网格包括 612 个点，间距为 0.5 米（见 [图：mannheim/compass/802.11] 中的蓝色标记）。在离线阶段，我们在每个参考点收集了 110 个信号强度样本，总共收集了 72,600 个样本。我们花费了超过 10 小时收集所有数据，但我们要指出，对于定位系统的实际部署，20 个信号强度样本和网格间距为 1.5 米的网格将足够，将时间消耗减少到不到半小时。格式：t="时间戳"; id="扫描设备的 MAC 地址"; pos="扫描设备的物理坐标"; degree="用户携带扫描设备的朝向"; "MACofResponse1"="信号强度值

搜集汇总

背景与挑战

背景概述

该数据集包含802.11无线接入点的信号强度数据，用于支持COMPASS定位系统的训练和定位阶段。数据集提供了详细的测量方法和配置信息，适用于无线网络和定位系统的研究。