La Piattaforma LABNET per il Telelaboratorio A Telelaboratory Platform ___________ LABNET: A Telelaboratory Platform Oreste Andrisano Franco Davoli Luigi Paura Stefano Vignola Sandro Zappatore Bologna 25 Febbraio 2004

MAIN GOALS User Classes Application fields High School University To develop a H/W and S/W architecture for the remote control of distributed real laboratory equipment at various complexity levels. To offer access to the physical resources on the basis of different users’ needs, skills and fields. Telecommunication systems measurement & testing Telecommunication networks measurements & testing Other application fields in engineering and physics Application fields High School University User Classes Research Educational SME Bologna 25 Febbraio 2004

LABNET-Methodologies Development Guidelines Design of the Software Architecture and development of LABNET Server and Client sides Design and set-up of experiments on the “Telecommunication Measurement Testbed” Design and set-up of experiments on the “Networking Testbed” Definition of interfaces for the interconnection of external laboratories (e.g., CIRA wind tunnel) Bologna 25 Febbraio 2004

Technical and Methodological Aspects Main Achievements Technical and Methodological Aspects Development of the drivers for the control of the instrumentation the Labnet Server the End-User Interfaces (GUI) the “Experience Manager” Design and set-up of the Experiences the related Documentation Bologna 25 Febbraio 2004

Main Achievements Scientific Aspects Study and Design of Protocols Suitable for the proposed Integrated Learning System (ILS) Design of a Software Architecture for the remote access and control of the Laboratory Environment Performance evaluation of the system Study and design of scalable audio/video coders for multimedia network applications Evaluation of the effects of satellite link fading on the video stream quality, using different coding schemes and/or data packetization Bologna 25 Febbraio 2004

Why a specific Software Architecture Heterogeneity of physical interfaces and communication protocols Each class of instruments is characterized by a specific physical interface and communication protocol for the remote access to the equipment. Heterogeneity of development environments In general, each class of instruments is provided with a specific software development kit for data gathering and reporting (e.g., LabView for oscilloscopes, voltmeters, etc., HP-Openview for routers, etc.) Bologna 25 Febbraio 2004

Why a specific Software Architecture Heterogeneity of the access technologes The system must allow an efficient use of the laboratories by users exploiting different types of access technology (e.g., ISDN, xDSL, leased lines, …) Educational Sessions often involve a great number of user stations The multimedia streams with the information produced by the instruments and by network and telecommunication facilities must reach the student stations in an efficient way (without waste of transmission resources) Access management The system must be able to allocate the proper resources for each requested experience, thus avoiding conflicts among different users Bologna 25 Febbraio 2004

Why a specific Software Architecture GUI suitably designed for the ILS mission The attention of the users should be focused on the specific features of the experiment being performed Only a subset of the instrument’s front panel controls is actually reproduced on the client side, according to the specific experiment, the depth of the experience and, possibly, the users’ skills The GUI allows to reproduce more than one device on the same page, thus providing a unified view of the set-up ready to be used, rather than a mere group of instruments. Bologna 25 Febbraio 2004

Reflecting the requirements in the implementation Client side Lecturer/Instructor station Two different client stations Student station To connect to the laboratory environment, only a generic browser with Java2 plug-in is needed To the LABNET Server INTERNET Remote users Bologna 25 Febbraio 2004

Reflecting the requirements in the implementation Client side selects and initializes the desired experience fully controls the “virtual” devices involved in the experience Lecturer Station monitors the presence of the student stations delegates the control of the experience to a specific student station communicates with LNS by using unicast packets (TCP) passively participates in the experience, showing the user the current state and values of the “virtual” devices Student Station receives data from LNS by means of multicast packets communicates with LNS by using unicast packets whenever designated by the lecturer

Reflecting the requirements in the implementation Server side Network Measurement Testbed Telecommunication Other Laboratories INTERNET LABNET SERVER Multicasting Authentication Registration Resource Management Protocols Experiences Network Measurement System Control Module Telecommunication Measurement System Control Module Other Laboratories Interaction Module between Network and Telco. Measurement System Bologna 25 Febbraio 2004

Client/Server Architecture Data Flow Diagram Browser Get <HTML Page> Web Server HTML Send <HTML Page> Send Applet Applet Send <Command> LABNET Data Server Send <Result> LABNET Server Host Client Bologna 25 Febbraio 2004

Labnet Server Architecture TLC Measurement Testbed Labnet Server Protocol Internet Suite Protocols Multicasting Front-end Server Bridge Data Repository Experience Manager Experience Manager WINDOWS LINUX Labview VI Vi2 Vi3 Daemon Agents Scripts TLC Measurement Testbed Networking Testbed Function Generator Oscilloscope Spectrum Analyzer Router Matrix PC

Labnet Server Architecture Experience Manager LNS Experience IDs, variables Experience Manager Device IDs, Commands/Results Testbeds Bologna 25 Febbraio 2004

LNS Communication Protocol Labnet Server Architecture LNS Communication Protocol LNSP is an ad-hoc communication protocol for data transfer between LNS and Experience Manager. The Protocol Data Unit consists of a header (referring to a specific experience) and zero, one, or more data “containers” The data “container” is a structure for the variable (scalar or vector) encapsulation. LNSP exploits the Internet suite for the actual exchange LNS LNSP TCP/IP TCP/IP LNSP è il protocollo di comunicazione sviluppato ad hoc utilizzato tra LNS e Gestore. L’elemento di comunicazione è un pacchetto costituito da un header (che permette di identificare esperienza numero sequenza …) e da zero o più container. Il container è la struttura utilizzata per l’incapsulamento delle variabili. LNSP si poggia sulla suite TCP/IP LNSP Experience Manager Bologna 25 Febbraio 2004

Labnet Server Architecture Format of a LNS Packet 1 2 3 4 5 6 7 8 bytes LSNP Header (24 bytes) Timestamp (Sec) Timestamp (microsec.) Number of containers Sequence Number EXP # Pack type command Packet Length Frag # tot. frag. remote port Container Header (16 bytes) Total element Total element 2 elem type Variable Name ACTUAL DATA OF THE MENTIONED VARIABLE ….. Variable Name (cont) Container Payload (max. 4056 bytes) the related field in the LSNP Header As many containers as specified by Container Header (16 bytes) Total element Total element2 elem type Variable Name ACTUAL DATA OF THE MENTIONED VARIABLE ….. Variable Name (cont) Container Payload (max. 4056 bytes) Bologna 25 Febbraio 2004

LNS Labnet Server Architecture The Main Loop Repository Client domain Start Repository Descriptors of the experiences Main Configuration Hash table of variables List of the connected stations Initialization of all the lists, tables and internal structures Internal ACLs Open network sockets Client domain UDP or TCP Packet Decode packet and related containers (if present) Wait for a Packet According to the LSP, prepare an answer and send it to clients or exp. manager Exp. Manager domain Bologna 25 Febbraio 2004

An example: initialization (1) Labnet Server Architecture LNS Communication Protocol An example: initialization (1) Launch the experience N LNS Initialize the experience N Experience N successfully initialized Experience Manager Il primo problema che il gestore deve affrontare è il controllo della disponibilità della strumentazione interessata dall’esperienza e l’inizializzazione della stessa. Per questa operazione si prevede un meccanismo descritto in maniera semplificata nell’animazione presente nel lucido corrente e nel successivo. Initialize Equipment 1 Equipment 1 successfully initialized Initialize Equipment 2 Equipment 2 successfully initialized ……. ……. Initialize Equipment M Equipment M successfully initialized Testbeds Bologna 25 Febbraio 2004

Labnet Server Architecture LNS Communication Protocol An example: initialization (2) Exp_1_var 1 = x Exp_1_var 2 = y Exp_1_var M = z ….. LNS Exp1 Var 1 Exp1 Var 2 Exp1 Var N Allocate var 1 of Exp 1 and set Exp_1_var 1 = x Allocate var 2 of Exp 1 and set Exp_1_var 2 = y Allocate var M of Exp 1 and set Exp_1_var M = z ….. Experience Manager get_default_value_var 1 Let default_value_var 1 = x get_default_value_var 2 ….. Let default_value_var 2 = y ….. get_default_value_var M Let default_value_var M = z Testbeds Bologna 25 Febbraio 2004

Labnet Server Architecture LNS Communication Protocol An example: initialization (client side) Master Station Java Applet Experience N ready: Launch the specific applets Display the default values of variables Select the experience N LNS Initialize the experience N Experience N successfully initialized Bologna 25 Febbraio 2004

Labnet Server Architecture The actual communication Java Applet LNS Exp1 Var 1 Exp1 Var 2 Exp1 Var N Experience Manager Testbeds Bologna 25 Febbraio 2004

Telecommunication Measurement Testbed Bologna 25 Febbraio 2004

Network Measurement Testbed Bologna 25 Febbraio 2004

External Laboratories CIRA Wind Tunnel in Capua Connected via HDSL at 2 Mbps Measurement of total pressure loss on bi-dimensional model in wind tunnel CT1 All main parameter setting remotely controllable and measurement displayed Bologna 25 Febbraio 2004

Synthesis of Digital Band-Pass Modulation Systems via DSPs “Telecommunication Measurement Testbed” Examples of Available Experiences Radio Links and Modems Satellite Other Measurements (High School - University) Synthesis of Digital Band-Pass Modulation Systems via DSPs (BFSK, BPSK, QPSK, WCDMA…) Measurements on Nortel Dasa equipment (with or without emulated satellite link) Active filtering Fine-tuning of a free FM oscillator Multipath ISI (2- or 3-ray channel) Measurements of noise effect on H.261 and MPEG coding (with emulated satellite link) Analog Modulation AM FM DSB spectra / effect of synchronization loss RF Interference (Notch effect) BER Measurements for QPSK, varying Eb/No and coding rate, with bandwidth estimation Bologna 25 Febbraio 2004

“Networking Testbed” Examples of Available Experiences Measurements on networking equipment Routing QoS VoIP Measurements at various Internet stack levels and on hetereogeneous access networks (Ethernet, ATM, Frame-Relay, … ) Building a network infrastructure based on a static/dynamic routing policy Video streams transmission on best-effort netwoks with: RSVP DiffServ QoS and P-QoS evaluation by varying the traffic load offered to the channel Performance evaluation of different protocols TCP congestion control with different TCP implementations (Reno, Tahoe, Vegas), varying the channel bandwidth RIP/OSPF Routing table visualization in the presence of network topology changes Real time measurements of Jitter Queue length TCP goodput Packet loss Signalling trace Bologna 25 Febbraio 2004

Performance Evaluation Measured traffic vs time during the session related to an experiment on analog modulation. The client is connected to the server via a transmission line at 640 kbps (dotted line) and at 128 kbps (solid line). Bologna 25 Febbraio 2004

Evaluation of educational impact Serveral experiences have been tested in both university and high school settings. In particular: Training courses for the Ministry of Communications Educational Project DIST – Università di Genova Classes in Telecommunication Networks, Telematics, Digital Communications ITIS “Augusto Righi” - Napoli ITIS “Maserati” - Voghera Bologna 25 Febbraio 2004

From the current situation … Future Developments From the current situation … INTERNET Networking Testbed CNIT WAN Remote users Capua Wind Tunnel Labnet Server The “Device Under Test” (DUT) and the Instrumentation of each Testbed are in the same location Telecommunication Systems Testbed

are distributed over the Future Developments … to Distributed Cooperative Laboratories (EUROLABNET) Control Network DUT DUT Instrumentation and DUTs are distributed over the various Labs involved in the experiment User Measurement Network Labnet (GRID) Server

Thanks to Luigi Battaglia Antonio Iudici Gianluca Massei Marta Pasi Amedeo Scarpiello Giuseppe Spanò Nunzia Ristaldi Davide Vicedomini Alfonso Vollono Andrea Zinicola ….. And also to Nicola De Lorenzo Luigi Di Fraia Piergiulio Maryni Umberto Pallotta Gianmarco Romano Bologna 25 Febbraio 2004

Sistema radio digitale CTR 210 HD/7 Siemens Telecomunicazioni S.p.A. (MI) TX1 RX1 DATA IN Probe IF out Segnale banda base: 8448 kbps Banda Radio Frequenza: 7,125 – 7,425 GHz Frequenze Intermedie: 231 MHz (Tx), 70 MHz (Rx) Codice: HDB3/NRZ Modulazione/codifica: 16 TCM (Trellis Code Modulation) IF out Probe RF out LO RF out RX2 RF in DATA OUT Decodificatore di Viterbi con quantizzazione soft a 3 bit Traffico equivalente a 128 canali telefonici Ridondanza per rivelazione e correzione degli errori (FEC) Due canali di servizio a 64 Kb/s IF in A B CKS

Maschera di emissione a frequenza intermedia e BER – BANCO DI MISURA – Maschera di emissione a frequenza intermedia e BER DATACOM/TELECOM ANALYZER TX Pattern di bit a 8 Mb/s RF SIGNAL GENERATOR DATA IN MIXER Data out Data in Segnale a 231 MHz Probe IF out Portante Fqz. : 301 MHz Level : 5 dBm IF out Segnale a 70 MHz LO Probe RF out NOISE GENERATOR RF out RX RF in SPECTRUM ANALYZER Directional Coupler DATA OUT IF in FC : 70 MHz SPAN : 10 MHz A B CKS

TELEMISURA via HTTP BANCO DI MISURA Server PC INTERNET Client WEB SERVER Client CODICE JSP Applets JAVA DataSocket SERVER PC LABVIEW INTERNET BROWSER GPIB Board HTML Applets JAVA Server CNIT NAPOLI BANCO DI MISURA

REMOTIZZAZIONE DEL BANCO DI MISURA RISPETTO AL WEB SERVER Client PC Server BROWSER WEB SERVER HTML CODICE JSP Applets JAVA INTERNET Applets JAVA PC DataSocket SERVER CNIT NAPOLI LABVIEW CNIT PARMA GPIB Board BANCO DI MISURA

AMPLIAMENTO DEL BANCO DI MISURA: Diagramma ad occhio – Costellazione TCM DATACOM/TELECOM ANALYZER TX Pattern di bit a 8 Mb/s RF SIGNAL GENERATOR DATA IN MIXER Data out Data in Segnale a 231 MHz Probe IF out Portante Fqz. : 301 MHz Level : 5 dBm IF out SPECTRUM ANALYZER Segnale a 70 MHz Probe RF out LO NOISE GENERATOR FC : 70 MHz SPAN : 10 MHz RF out RX RF in Directional Coupler DATA OUT COSTELLAZIONE TCM 16 STATI OSCILLOSCOPE IF in DIAGRAMMA AD OCCHIO TRA 1 TRA 2 TRIGGER A B CKS