Performance measurement for mobile data streaming Florin Sandu a,1 , Iuliu Szekely a,1 , Dan Robu b, ⁎, Alexandru Balica c,2 a “Transilvania” University of Brasov, Bd Eroilor 29, 500029, Brasov, Romania b Siemens Program and Systems Engineering Romania, Bd. Mihail Kogalniceanu 21, 500090, Brasov, Romania c Eservglobal Telecom Romania, Calea Floreasca 167, 014459, Bucharest, Romania abstract article info Available online 23 November 2009 Keywords: Data streaming Remote monitoring Technical limitations GPRS UMTS Streaming via radio increased in mobile communications, with specific advantages for remote monitoring: distant and ubiquitous controlled and controlling parts. The authors used a real PLMN for mobile data acquisition and transmission. Virtual instrumentation was used for programming at the mobile or fixed probe and client side. At the probe it was used as a portable Digital Oscilloscope whose user-interface was emulated at the client like operating it on-site (non-perceptible delay, 3GPP real-time service [http:// www.3gpp.org; (1)]. The goals were the identification of technical limitations, specific test methods and QoS assessment for mobile remote-measurement (by the delay parameter, related to round-trip time and jitter). © 2009 Elsevier B.V. All rights reserved. 1. Introduction Wireless cellular networks are nowadays omnipresent, being available now to more than 3 billion subscribers worldwide and having a great impact on their personal and professional life. The permanent and almost ubiquitous world cellular networks can be used for data transmission in civil/general purpose. The use of data acquisition and data transmission over PLMN (Public Land Mobile Network) can save time and enhance accessibility (from multiple locations) with minimum footprint from the technology and equipment point of view. Due to the fact that the infrastructure is already in place, the added-value of mobile remote measurement is cost efficient. The infrastructure is constantly extended and new wireless transmission technologies are developed (like WiMAX as a telecommunication backbone for broadband Internet access). Hence, the quality and availability are constantly improved and maximized for data transmission, thus making the wireless solutions available for small business and/or remote areas. Availability and mobility (hand- over and roaming) provided applicability and increased usability to further domains of activity such as remote measurement and measurement on the move that are the object of the present study. The authors accomplished a case study based on a workbench with high speed data acquisition by a digital oscilloscope and with real- time transmission [1] via mobile networks—GSM/UMTS–GPRS [2,3] provided the transport. The “real-time” concept in mobile networks is characterised by the fact that allowed transfer times are limited (lower) by the conversational nature of the architecture. It must be also considered that the time relationship between information entities (“time-stamps” of “events”—in the interrupts' treatment perspective) should not be affected by streaming. In multi-media, delays or jitter have rather perceptual-physiologic (upper) limits—as much as human perception of video and audio allows. In the present case study, time relationship is carefully controlled by the data acquisition subsystem, and before packing at the transmitter side, the acquired data can be sent without strict timing, provided that the transfer is fast-enough, and reconstruction at the receiving side can be done precisely, inside the same perceptual delay allowed: for instance, for an usual oscilloscope, this must be lower than “retina persistence” which must be lower than “phosphor persistence”—so, again, a human perceptual limit like for normal video streaming (e.g. mobile video-telephony, mobile “video on demand”, mobile IP-TV etc.). Characteristic to this approach of data streaming for remote measurement is the use of a real, existing PLMN. The test-bed [4] had the architecture of Fig. 1, with a Radio Access Network (BTS—Base Transceiver Station/Node B-UMTS Base station, BSC—Base Station Controller/RNC—Radio Network Controller), Switching Center (MSC— Mobile Switching Center and TRAU—Transcoding and Rate Adaption Unit) and a Data Center (SGSN—Serving GPRS Support Node and a GGSN—Gateway GPRS Support Node from CISCO, [5]). Both the probe and the client can be fixed or mobile, local or remote (see the configurations of Figs. 2 and 3). Different scenarios can be imagined, with mobile units-under-test (e.g. vehicles, patients) having attached data loggers and transmitters and/or mobile surveillance– diagnose–intervention teams etc. From the measurement point of view, the authors considered the state-of-the-art in the field of remote measurement and distrib- uted measurement systems relying on wireless telecommunications networks. Computer Standards & Interfaces 32 (2010) 73–85 ⁎ Corresponding author. Tel.: + 40 268409156. E-mail addresses: sandu@unitbv.ro (F. Sandu), szekelyi@vega.unitbv.ro (I. Szekely), dan.robu@siemens.com (D. Robu), alexandru.balica@eservglobal.com (A. Balica). 1 Tel.: + 40 268478705. 2 Tel.: + 40 212332115. 0920-5489/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.csi.2009.11.001 Contents lists available at ScienceDirect Computer Standards & Interfaces journal homepage: www.elsevier.com/locate/csi