Wireless

Preliminary

At the ESRF, the Wireless LANs are used for 4 different applications:

• "Hotspot" where visitors can connect to the Internet (mainly in the Experimental Hall and in the Guesthouse).
• "Meeting rooms" where several dedicated laptops can connect to the internal network for the purpose of a talk (around the public meeting rooms only).This application is replaced by the "Internal user" application starting from February 2011.
  
• "Machine" where dedicated laptops can connect to the Machine (Accelerator) network for maintenance operations (mainly in the Technical Gallery).

• "Internal user" where any user with a valid site password can connect. The first version, limited to Windows laptops only, has started in December 2010, with a general introduction on February 4, 2011.

The wireless technology

Instead of using physical cables connecting a personal computer to a network wall plug linking in turn to a single high-performance Ethernet switch, Wireless Ethernet is based on the distribution of many "access points":

• an access point is physically connected to the Ethernet wired network on the one hand, and relays the network access to the air via an antenna on the other hand
• a personal computer having a wireless Ethernet interface (via an internal antenna) catches the signal propagated by the nearest access point

Why do we still use wires in ESRF offices ?

At the ESRF, the wireless technology cannot replace the wired technology in the offices, because of the performance gap: today, most personal computers enjoy a private connection of either 10Mbps (MBit/sec.) or 100Mbps. The usual wireless (IEEE802.11b "WiFi") offers a 11Mbps link shared among a possibly large number of computers. The newest wireless standard (IEEE802.11n) increases the optimal bandwidth up to 300Mbps, but decreases a lot when the signal becomes weaker, and the problem of sharing the available bandwidth remains.

In the future, the performance gap even gets wider with the spreading of 1000BaseT (1000Mbps on copper cable), which is already available on several Beamlines.

Where do we use wireless at the ESRF ?

Wireless is intensively used on the 'Machine', for maintenance and tuning in the Technical Gallery and at other places around the ring.

Wireless is available in all ESRF public 'Meeting rooms', for a set of registered PCs only. This access is progressively replaced by the connection to the internal network mentioned below.

Wireless is also available in the EXPH, the Control Room, and more and more offices areas for the following applications:

• connection to the internal network 
• hotspot / public access (Internet access for the beamline visitors and the Guesthouse guests). In the EXPH area and near the public meeting rooms, this public access network is now protected by a Captive Portal. This device captures the first Web connection of a PC to the wireless network, and presents a Web page saying that the public access network is reserved for ESRF visitors. Visitors are allowed to use the public access network, while internal users are denied.

How do we use wireless at the ESRF ?

• Internal network: following many virus alerts, the ESRF cannot allow connecting any computer onto the internal network. Two protections co-exist, the first being progressively replaced by the second:
  • access to the internal computing resources in the 'Meeting Rooms' and the 'Machine' network: the connection is based on CISCO's LEAP protocol, which is a secure IEEE802.1X EAP authentication solution.
    

    Today, only Windows computers duly registered and configured by the Computing system administrators (Network Unit or Windows Unit) can use this Wireless network. This prevents "wild" connections onto the sensitive Machine's network, but also the connection onto the general network of "external" computers in or around our meeting rooms.

  • access to the internal network in the EXPH and office areas: only Windows PCs can connect, and only PC installed by ESRF administrators.
• A hotspot / public access Wireless network is available in the EXPH, the Guesthouse, and the meeting rooms and gives a direct access to the Internet. ESRF visitors are invited to use this so-called "public-access" network.

How to connect to the public-access network (visitors)

Please follow the instructions in our User's Manual for guests  (intranet).

How to connect to the internal network

Please follow the instructions in our User's Manual for staff (intranet).

The products in use

The infrastructure relies on CISCO lightweight Access Points with high-availability central controllers.

Most laptops nowadays integrate a wireless interface. This one must be "Wi-Fi certified" (have a look at http://www.wi-fi.org) and be careful with the European version (EMEA) of the interface, whereas more radio channels are used than in the US version.