CRAWDAD novay/cosphere

Network traces on the personal mobile devices of 12 trial participants over a period of one month in the February/March 2007 time frame.

The CoSphere (Communication Context for Adaptive Mobile Applications) trial gathered network traces on the personal mobile devices of 12 trial participants over a period of approximately one month in the February/March 2007 time frame.

date/time of measurement start: 2007-02-01

date/time of measurement end: 2007-03-13

collection environment: The objective of the CoSphere Trial is to collect network availability and network status traces as observed on multi-homed devices of real users. We ran this experiment with 12 users in a six week period in February/March 2007, logging cellular, 802.11 wireless lan, Bluetooth and (indirectly) fixed USB events on Windows CE devices.

We want to use the traces of this experiment to investigate the possibilities for 'experience-based network resource usage on mobile hosts'. The basic idea is that knowledge on the mobility patterns of the user helps to optimize the usage of network resources by applications on mobile hosts, especially for those applications that have a degree of delay-tolerance. We have focused on the prediction in time of a mobility event of interest, such as 'getting in range of the home 802.11 network'. 

We propose a method using preceding events as predictors for the event of interest, as discussed in the papers Density Estimation for Out-of-Range Events on Personal Mobile Devices and Predicting mobility events on personal devices.

network configuration: The CoSphere trial gathered network traces on the personal mobile devices of 12 trial participants over a period of approximately one month in the February/March 2007 time frame. The dataset contains information from three different wireless network interfaces - cellular, 802.11 and Bluetooth - and provides insight into the richness and dynamics of the visibility of wireless networks from a user oriented perspective.

data collection methodology: The traces were collected using the Network Abstraction Layer (NAL) software available at http://cosphere.novay.nl/nal/.

Traceset

novay/cosphere/visibility

Traceset of the personal mobile devices of 12 trial participants over a period of one month in the February/March 2007 time frame.

• file: cosphere.tar.gz
• description: The CoSphere (Communication Context for Adaptive Mobile Applications) trial gathered network traces on the personal mobile devices of 12 trial participants over a period of approximately one month in the February/March 2007 time frame.
• measurement purpose: User Mobility Characterization, Social Network Analysis, Opportunistic Connectivity
• methodology: The dataset contains the following visibility information:

- the cellular operator name, operator number, location area code (LAC), and cell id (CID) of the associated base station (monitored continuously, storing a new base station when the association changes)

- the cellular operator name and operator number of all in-range cellular networks (scanned once every 5 minutes)

- the service set identifier (SSID), the basic service set identifier (BSSID) and the association state of all in range 802.11 access points (monitored during 1 minute, every 10 minutes)

- the Bluetooth device address (BD_ADDR) and device name of all in range Bluetooth nodes (scanned once every 5 minutes)

- the remaining battery power percentage

- device attachment to AC power

novay/cosphere/visibility Trace

• arff: Network traces of the personal mobile devices of 12 trial participants over a period of one month in the February/March 2007 time frame.

• configuration: After a scan on a network interface, the visibility state is taken to be constant until the next scan, which means that for 802.11 a change may occur every 10 minutes (more often when the user interacts with the device) and for Bluetooth a change may occur every 5 minutes.
• format: The traces are stored in files of the Attribute-Relation File Format (ARFF, see http://www.cs.waikato.ac.nz/~ml/weka/arff.html ), in sparse form. Every line describes the visibility of cellular, 802.11 and Bluetooth networks at a specific time. Lines are not printed at regular intervals, but only when the current visibility state differs from the state described in the previous line.

The sparse .arff file starts with a section describing the 'attributes', followed by a 'data' section describing the value of these attributes. The sparse notation assigns a default value of 0 (zero) to attributes not specified on a data line. We use binary values to indicate whether a base station, access point or node is in range.

Example .arff file: @RELATION visibility @ATTRIBUTE timestamp date % attr 0 @ATTRIBUTE after-reset {0, 1} % attr 1 @ATTRIBUTE batterylevel NUMERIC % attr 2 @ATTRIBUTE on-ac {0, 1} % attr 3 @ATTRIBUTE "cid-copname01-copnumber01-lac1398-cid82300" {0, 1} % attr 4 @ATTRIBUTE "cid-copname01-copnumber01-lac1398-cid23897" {0, 1} % attr 5 @ATTRIBUTE "wlap-inrange-ssid58034-bssid27992" {0, 1} % attr 6 @DATA {0 2007-03-10T16:08:58, 1 1, 2 81, 4 1, 6 1} {0 2007-03-10T16:10:46, 2 80, 4 1} {0 2007-03-10T16:12:06, 2 80, 5 1}

The timestamp, afterreset, batterylevel and on-ac attributes (numbers 0-3) are in every .arff file. The rest of the attributes refer to the visibility of network resources, using the following naming scheme: - cop-copname; nr;-copnumber; nr; Cellular operator - cid-copname nr;-copnumbernr;-lac; nr;-cid; nr; Currently associated cell - wlap-inrange-ssid; nr;-bssid;nr; In range 802.11 access point - wlap-assoc-ssid; nr; -bssid; nr; Currently associated 802.11 access point - btnw-bdaddr; nr; In range Bluetooth node These attributes vary per participant. When the afterreset attribute is set the device was restarted in between the time of the last line and the time of the current line. For convenience, we have included a Python script to transform the .arff files into .txt files in which the full names of visible network entities are used (tested under Python version 2.5.1). Running; python arfftotxt.py */*.arff from the directory of this README file will generate the .txt files.