The Wireless Library: Technical and Organizational Aspects
While most universities deploy wireless networks to cope with the needs of students and staff, many libraries are still uncertain
whether and how they should provide Internet access to their customers. The demand from users may be acknowledged but it is
unclear how such a demand could be met without added security risks for the library and what would be the impact on library
The change in raw materials
The dawn of the electronic age in libraries is not solely due to the introduction of online catalogues. Most modern publications
are now born digital and more and more of these publications are delivered in electronic only format, either on hard copies
like CDs or DVDs or just in time to the user's desktop over the network. Many PhD theses are only available online as they
belong to the few publications which are fully under the control of the university system and are therefore among the first
to experiment with new media. Many libraries operate large servers to provide storage space for such online data. Apart from
offering fast access such online storage seems to be considerably cheaper than the traditional shelf system with its necessary
building infrastructure. Long term storage issues appear to be solved at least with respect to replacing the capabilities
The change of user expectations
In the past users were quite happy to walk up to centralized terminals in order to start their queries and then to copy the
information from books or journals either by hand or with copy machines. Nowadays users want to store their information on
personal storage - even if they print it out for readability because they do not yet want to afford expensive high quality
displays - and therefore require means to transfer digital material from the library directly onto their private machines,
copyright permitting. Typical service offerings in libraries include the data transfer to floppy disks or to CDs, rarely to
modern USB memory sticks. These services become increasingly difficult to deliver as more users start to use them.
They are also becoming obsolete, as users start to bring their private notebook computers or personal digital assistants into
libraries to transfer the data directly to these devices. Even more the machines can be used to access any information provided
by libraries and even connect to the Internet. The most noticeable advantage for users is the fact that they can work in a
familiar environment, once a connection to the worldwide network has been established. In the computer science environment
such users are called "nomads" or sometimes jokingly "road warriors" as unlike the traditional paper-centric humans they carry
all their data - their belongings - with them and are able to work anywhere and anytime. The percentage of nomadic students
in the universities is increasing every year.
The first encounter between librarians and such nomads typically happens during their quest for a power socket. While laptops
are autonomous systems for a period of time their batteries need to be recharged quite regularly. As in every household, also
in most libraries sockets are never where they should be from a user perspective. While recharging their laptops users are
confined to their workplace because of the possibility of theft. Unsecured laptops are an easy prey for thieves. Again most
public places offer no possibilities to secure laptops, although in most cases, especially libraries, wall attached hooks
would be more than sufficient. Such hooks could be used to attach a personal Kensington cable with which a laptop can be chained
to its place.
A rather nice alternative can be found in Freiburg: lockers have been equipped with power sockets so that users can recharge
their machines while having lunch in the cafeteria. Needless to add that these lockers are under constant human surveillance.
Technical solutions for a wireless environment
User access to the library's data network and possibly the Internet can be offered via network sockets in certain areas or
user desks. Most likely during the design of the network attention was given to administrative needs and not to user needs,
as laptops were not widely spread. Therefore network sockets are not where they should be, given modern requirements. The
cost of reinstalling new network cabling is prohibitive in most cases.
There is a solution to carry data traffic over standard electrical 240V wiring, called Powerline. Powerline modules are relatively
small and cheap. All powerline modules on one electrical circuit form a common network with a peak performance of up to 14
Mbit/s. One module is required to connect this network to an existing IP switch. The installation of such modules is straight
forward and requires little or no planning. A powerline network corresponds to a classical Ethernet. However, experience shows
that the peak data rate is rarely achieved and that electrical interference may seriously disrupt the data traffic. Such interferences
come from switching on lights or from a printer or even a computer attached to the same electrical circuit. It is wishful
thinking to have the powerline technology incorporated into laptop power supplies. With powerline users are again confined
to their desks or cubicles if they want to access digital data, even when their laptop batteries are fully charged. Mobility
Since about five years wireless IP networks are available. The technology is called WLAN or WiFi and there are several standards.
The oldest and most common standard is IEEE 802.11b which operates in the 2.4 GHz range and allows a data rate of up to 11
Mbit/s in one cell. This data rate is shared between all computers in this cell. The new standard 802.11g is fully compatible
with 802.11b and offers up to 54 Mbit/s. The 802.11a standard operates in the 5 GHz range and also offers up to 54 Mbit/s.
It is expected that laptops will soon understand all three standards; modern machines will at least adhere to 802.11b/g. The
maximum energy of a sending station must not exceed 0.1W and is typically around 0.03W. This is in contrast to mobile phones
which use up to 2W (in the 900 MHz range). The range of this wireless technology varies. Under ideal circumstances 300m can
be covered; in concrete buildings the range may drop to 20-50m. The range can be extended with special antennas and under
ideal conditions (across a lake) up to 10km have already been achieved.
In any case the current WLAN technology allows to provide widespread network connectivity in libraries. Relatively few access
points suffice to completely cover user work areas as well as the most often used shelf spaces. For best performance the access
points should be connected to the network with traditional cables. The most advanced systems connect special antennas via
a traditional TP cable to a central management station. There are also access points with a wireless uplink to a central switch
as well as access points with powerline uplink. A WLAN based network can therefore be installed very quickly at low cost.
This makes it ideal for libraries. The best locations for access points are usually found by trial, based on educated guesses.
It should be added that there are specially designed access points and antennas which match special conservational or design
needs. It must be pointed out that WLAN is no replacement for proper network cabling. Proper cables allow much higher speeds,
offer better security and are almost immune to interferences from external sources.
Bluetooth is another wireless technology which operates in the 2.4 GHz range but it uses the spectrum in a different way.
The maximum data rate is 1 Mbit/s and the sender uses less than 0.01W. Thus Bluetooth is ideally suited for devices with small
batteries, like mobile phones or personal digital assistants (PDA). However, the range is reduced to some 10m. Bluetooth LAN
access points provide the same functionality to PDAs as the WLAN access points do for laptops. Experience shows that both
technologies can coexist.
Most laptops as well as PDAs have an infrared interface. The properties of light make such interfaces ideal for point to point
communication and a classical application is the direct exchange of electronic business cards. Internet traffic can also be
sent over infrared connections with a maximum speed of 4 Mbit/s for each individual connection. Therefore it makes sense to
offer infrared access points at certain highly frequented locations, so that users can at least update their personal information
from time to time, even if they cannot make use of the options offered by a WLAN network.
Given the right set-up all three technologies can be used in one single network without extra management overhead. It therefore
makes sense to provide a WLAN network in a library based on IEEE 802.11b/g and to supplement it with a number of Bluetooth
access points and with several infrared access points. In addition a number of network sockets should be offered in cubicles
to allow for high bandwidth communication with multimedia servers. Powerline technology can be used as a substitute for cables
in areas where performance or throughput are not an issue.
Organizationial solutions in a library environment
A major topic in wireless networking is security. Many papers have been published on the various loopholes of different implementations.
The experiences gained in universities however prove that wireless networks can be securely integrated into an existing environment.
Rather than individually connecting the various access points to the production network (the intranet), it is better to set
up an entirely separated network in order to interconnect the access points. This network should not have any connection to
the library's intranet. While in former times such an approach required a separate cabling infrastructure, today's VLAN technologies
can be used to set up a logically separated network at no cost. Network administrators then no longer have to worry about
potential security hazards.
This separated network should be connected to the library network outside the firewall (if there is any) or Internet gateway,
so that users on the wireless network have the same privileges as any other user on the Internet. Access to the wireless network
(including the network sockets open to users) should be made as easy as possible. Otherwise support issues may turn into an
overwhelming problem. DHCP servers can supply user machines with IP addresses as soon as they connect to the network. It remains
a management issue to decide whether or not this separate network should be directly connected to the Internet. Most University
set-ups rely on authentication gateways where userid and password or other credentials are checked before individual connections
For libraries it may be a tedious job to authenticate users, which is also unnecessary as libraries are in the same situation
as many Internet cafes. Therefore their fairly advanced hotspot technology software for gateways can be used. It allows to
issue day accounts or weekly accounts to users "over the counter" with very little administrative overhead, if any. The fee
for such an access must not be prohibitive as otherwise people will be scared away from modern technologies for monetary reasons
In a University environment it is wise to integrate the library wireless network into the University's wireless security concept
to allow for roaming and to use a separate hotspot gateway for external users. It must be noted that eavesdropping is very
easy in wireless networks. It should be left to the users to secure their individual connections. This is done implicitly
by many mail clients when they contact their mail server via SSL-protected connections. Most users will be used to setting
up an encrypted tunnel (IPsec) to their home institution before they start to communicate. The security of such encrypted
tunnels is far better than the security offered by access points; in fact current knowledge suggests that such security is
LIBER Quarterly, Volume 14 (2004), No. 2