Needs Of The Wireless Based Test Setup For Payload Testing In The Thermovacuum Chamber

Needs Of The Wireless Based Test Setup For Payload Testing In The Thermovacuum Chamber

Ravi J. Bagatharia, Prof. Sunera Kargathara

Department of Electronics & Communication, MEFGI, RAJKOT, GUJARAT

Mr. Anand Kumar

(LPID/EOSG/SEDA) SPACE APPLICATION CENTER ISRO, AHMEDABAD, GUJARAT

ABSTRACT

As the number of measurement and the technology increases for the thermovacuum testing, there is need to change the testing method for payload inside the thermovacuum chamber. In this paper we explore how wireless standards are helpful for the thermovacuum testing of payload. For this we studied and analysis different types of IEEE 802 wireless standards for application in thermovacuum testing of payload. Here we explain how to remove the long and bulky harness between the thermovacuum chamber and the ground checkout unit.

Key words Payload, Thermovacuum chamber, IEEE 802

wireless communication between the thermovacuum chamber and the ground checkout unit.

1. PRESENT TEST SETUP FOR THERMOVACUUM TESTING

   Figure below shows the present test setup for the thermovacuum testing of payload. Here the payload sitting inside the thermovacuum chamber is communicates with the Ground Checkout Unit (GCU) outside the thermovac chamber through the wires.

   1. INTRODUCTION

      The thermovacuum chamber is basically used to test the payload in the same environment as the space. It used for space environment simulation of payload. Inside the thermovacuum chamber different range of temperature and presser is created and check the working condition of the payload. For testing the payload there is ground check unit outside the thermovacuum chamber send the different types of data and command to the payload which is sitting inside the thermovacuum chamber through the wires [1]. As the number of measurement increases the number of cables are also increases, so harness of cables is increases and pass the cables inside the thermovac chamber is very difficult task. So, these are the limitation of current system and we are trying to explain how to remove these limitations by doing the

      Figure 1 The present test setup for thermovacuum testing

2. PROPOSED TEST SETUP FOR THERMOVACUUM TESTING

   Figure below shows the proposed test setup for the thermovacuum testing of payload. Here the payload

   sitting inside the thermovacuum chamber will interface to the interfacing card and the interfacing card will interface with the RF transmitter / receiver. Outside the thermovacuum chamber the ground checkout unit will interface with the interfacing card and the interfacing card will interface with the RF transmitter / receiver.

   Figure 2 The proposed test setup for thermovacuum testing

3. COMPARISON OF DIFFERENT WIRELESS STANDARDS

   There are different types of IEEE (Institute of Electrical and Electronics Engineers) 802 wireless standards are available like, IEEE 802.11 Wi-Fi, IEEE 802.15.1 Bluetooth, IEEE 802.15.4 ZigBee,

   IEEE 802.16 WiMax. Here all the standards are use the ISM (Industrial, Scientific and Medical) band for the communication. All these standards are use for different application and have different types of specification which are explain below.

   Bluetooth:

   The IEEE 802.15.1 standard is called Bluetooth standard. Bluetooth is a low tier, ad hoc, terrestrial, wireless standard and it is used for the short distance wireless communication. It is use the transmission frequency band of 2.4 GHz. It has packet data rate of 1 Mbps and can transmit up to 10 meter distance [2].

   ZigBee:

   The IEEE 802.15.4 standard is called ZigBee standard. It is used for wireless remote monitoring and control. It is use the transmission frequency band of 2.4 GHz. It has packet data rates of 20, 40, 100 and 250 Kbps. It has maximum range of 100 m for low data rates [3].

   WLAN/ Wi Fi:

   The IEEE 802.11 standard is called the Wi- Fi standard. Wi-Fi is an abbreviation for Wireless Fidelity and used for wireless local area networks (WLANs). It is used for transmit the web, e-mail and videos. It uses the transmission frequency band of 2.4 /

   5 GHz [4-5]. There are different types of WI fi standards are available all has different packet data speed like 11, 54, 600 Mbps. The maximum

   transmission range is 100 m. There are several types of IEEE 802.11 standards as follow [6-7].

   Standard	Data Speed	Frequency band	Release Notes
   802.11	2Mbps	2.4GHz	1997
   802.11a	54Mbps	5GHz	2001
   802.11b	11Mbps	2.4GHz	1999
   802.11g	54Mbps	2.4 GHz	2003
   802.11n	600Mbps	2.4/5 GHz	2009

   Table 1 The comparison of different Wi Fi standards

   Wi Max:

   The IEEE 802.16 standard is called the Wi- Max standard. The WI Max standard has same application as the wi- fi but it use the transmission frequency band of 2.3, 2.5, 3.5 GHz. It has packet data rates of 100 Mbps and 1 Gbps at the distance of 50 Km [8].

   There are basically two modes of wireless communications:

   1. Infrastructure mode:

      Any communication has to go through access point. One station need to send information to AP first, then AP sends it to the destination station. Here we cannot transmit the information directly to each other. The transmission range is increase in this mode. It is used by the majority of WLANs in homes, campuses, businesses, cafe, hotels, etc.

      Standard \ Specificati on	802.1 5.1 (Bluet ooth)	802.15.4 (ZigBee )	802.11 (Wi – Fi)	802.1 6m (Wi – max)
      Applicatio ns	Cable replac ement	Remote monitori ng and control	Web, Email, Video	Web, Email, Video
      Tx	2.4	2.4	2.4	2.3,
      Frequency	GHz	GHz,	GHz /	2.5
      Band		868/915	5.0	and
      		MHz	GHz	3.5
      				GHz
      Data Rates	1	250,	11/54/6	100
      	Mbps	100, 40,	00	Mbps,
      		20 Kbps	Mbps	1Gbps
      Modulatio	GFSK	O-	Compli	MIM
      n		QPSK,	mentar	O-
      Technique		ASK,	y code	SOFD
      s		BPSK	keying	MA
      			/
      			OFDM
      Max.	10 m	100 m	100 m	50Km
      Ranges		for low
      		data
      		rates
      Encryptio	4LFS	AES-	WEP	AES
      n	R –	128	algorit	or
      Technique	128		hm	DES
      s

      Standard \ Specificati on	802.1 5.1 (Bluet ooth)	802.15.4 (ZigBee )	802.11 (Wi – Fi)	802.1 6m (Wi – max)
      Applicatio ns	Cable replac ement	Remote monitori ng and control	Web, Email, Video	Web, Email, Video
      Tx	2.4	2.4	2.4	2.3,
      Frequency	GHz	GHz,	GHz /	2.5
      Band		868/915	5.0	and
      		MHz	GHz	3.5
      				GHz
      Data Rates	1	250,	11/54/6	100
      	Mbps	100, 40,	00	Mbps,
      		20 Kbps	Mbps	1Gbps
      Modulatio	GFSK	O-	Compli	MIM
      n		QPSK,	mentar	O-
      Technique		ASK,	y code	SOFD
      s		BPSK	keying	MA
      			/
      			OFDM
      Max.	10 m	100 m	100 m	50Km
      Ranges		for low
      		data
      		rates
      Encryptio	4LFS	AES-	WEP	AES
      n	R –	128	algorit	or
      Technique	128		hm	DES
      s

      Figure 3 – Infrastructure mode operation

   2. Ad Hoc mode:

   Here clients can connect to each other directly. Any station communicates to each other directly. This technique is used for short distance communication. It is used for special purpose and for a short duration of time.

   Figure 4 Ad Hoc mode operation

   Table below shows the brief comparison of all these wireless standards on the basis of their applications, Tx frequency band, data rates, modulation techniques, maximum range and the encryption techniques.

   Table 2 The comparison of different wireless standards

   All the wireless standards are also different in terms of their operating modes. Table below shows what type of mode can support by the different standards:

   STANDARDS	Ad Hoc	Infrastructure
   IEEE 802.11 a\b\g\n	Yes	Yes
   IEEE 802.15.1	Yes	No
   IEEE 802.15.4	Yes	No
   IEEE 802.16	Yes	Yes

   Table 3 – Modes of operation for the different wireless standards

4. CONCLUSION

After studied all these wireless standards we conclude that, the Bluetooth is used for the short distance communication, it has limitation in range. The ZigBee standard has limitation in data rates, it has very low speed compare to the other wireless standards. The Wi

• Max standards is very good in terms of its data rates and range, but there is requirement of wireless communication is within the lab, also the interference is high in the Wi Max compare to the Wi Fi. Also the Wi Fi components for different types of Embedded application are easily available. So, the Wi

• Fi standard is very suitable for the testing of payload in the thermovacuum chamber.

REFERENCES

1. A. Murari, L. Lotto, Wireless communication using detectors located inside vacuum chambers, Consorzio RFX, Associazione, Euratom- Enea Sulla fusione, C.so Stati Uniti 4, 35127 Padova,

   Italy, Vacuum 72 (2004) 149155

2. Institute of Electrical and Electronics Engineers. IEEE Std 802.15.1-2005, Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Wireless Personal Area Networks (WPANs), 14 June 2005. URL

   http://standards.ieee.org/getieee802/download/802.15.1

   -2005.pdf.

3. Institute of Electrical and Electronics Engineers. IEEE Std 802.15.4-2006, Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks (WPANs),

   8 September 2006. URL http://standards.ieee.org/getieee802/download/802.15.4

   -2006.pdf.

4. Institute of Electrical and Electronics Engineers. IEEE Std 802.11-2007, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, 12 June 2007.

5. Sheldon Lou, Wireless Communications, CSUSM.

   http://140.127.22.92/download/learn_web/99_new_Mul timedia_Comm/Wireless%20%26%20Mobile%20netw orks/WLAN-WiFi/Wi-Fi.ppt

6. Jeffrey D. Bombell, Wireless Networking, American Computer Technologies. http://www.infolink.org/pdf_files/wireless.ppt

7. Vijay K. Varma, Wireless FidelityWi-Fi, published on the IEEE Emerging Technology portal, 2006 2012.

8. Jan Magne Tjensvold, Comparison of the IEEE 802.11, 802.15.1, 802.15.4 and 802.15.6 wireless standards, September 18, 2007.