A new document from the Communications Alliance looks at the technology and regulations that need to be considered when planning a public WiFi deployment in Australia.

A new paper, produced by the Public WiFi Networks Group within the Communications Alliance and titled Public WiFi Networks Industry Information, has provided an overview of the current state of the public WiFi industry in Australia and the legal and regulatory obligations and technical requirements to be considered by new and existing operators of public WiFi networks.

The document also looks at the commercial models being employed around such networks, the emergence of new protocols that may significantly boost the capability of WiFi networks, and end user issues associated with WiFi connectivity.

“The proliferation of ‘smart’ mobile handsets, tablet computers and always-connected applications has contributed to what is being billed the ‘mobile data explosion’; a phenomenon seen throughout the developed world and is front of mind for most telecommunications carriers as they prepare their networks and growth strategies to meet the challenge and best harness this transformation of the mobile environment,” writes Public WiFi Networks Group chair Rob Haylock.

“Public WiFi networks have long been available throughout office environments and public areas such as airports and shopping centres for use as either a free or commercial service for mobile workers, travellers and shoppers, and appear likely to play a larger role in the national ‘connectivity matrix’ in years to come. The technical, regulatory and planning guidelines for public WiFi networks are, however, not as well defined in Australia as they are for mobile networks.”

While the document is purely for information purposes only and does not establish any compliance requirements for existing or new WiFi network operators, it does provide a high level overview on a number of issues including regulatory, technical and legal considerations.

The following article is a summary of the paper. To download the full document, visit www.commsalliance.com.au.

Regulation

The regulatory aspects affecting public WiFi are sometimes unclear or misunderstood.

According to the Telecommunications Act 1997 (the Act), network carriage to the public requires a carrier licence. Since a WiFi access link is a ‘network unit’ under the broad definition of the Act, then anyone operating a WiFi network needs to assess their potential for incurring legal obligations as a carrier.

Similarly, if someone is offering a service to the public over a WiFi link then that service would be a ‘carriage service’ as defined by the Act and they, too, would be bound by the requirements of a carriage service provider.

However, there is some flexibility for the operation of WiFi services.

When WiFi emerged as an alternative wireless access technology to mobile telephony networks in 2002, the then Minister for Communications, Information Technology and the Arts, Senator Richard Alston, determined under section 51 of the Act to exempt wireless networks from the need to be licensed in certain circumstances where a fixed line network providing the same service would not require a carrier licence.

In line with this determination, wireless equipment used to supply communication services to the public on a single premises (such as an internet cafe, an area of a shopping centre, an airport lounge, hotel or conference centre) does not require a carrier licence where the service is not to be re-transmitted.

Apart from these, the operation of WiFi equipment requires a carrier licence.

Issues have arisen, however, under the Telecommunications (Emergency Call Service) Determination 2009 as to whether or not a service provider supporting telephony and using WiFi is obliged to offer an emergency voice calling capability.

If a carriage service provider (CSP) is obliged to offer an ‘always on’ functionality for emergency calling and the power supply is interrupted, it is unclear what power back up arrangements that CSP would need to have in place.

A question could then arise about the nature of location information that might be made available to emergency service organisations in emergency communications and its reliability (e.g. verification by a trusted network operator versus end user assertion of location).

Technical issues

Public WiFi networks operate on the IEEE 802.11 family of standards and specifications, which defines wireless connectivity protocols with fixed, portable or moving devices in a local area.

A typical public WiFi network architecture consists of a single wireless access point (AP) or multiple APs, a wireless local area network (LAN) controller, a LAN Switch, a gateway and a router to connect to the internet.

Some public WiFi networks may restrict access and only allow authorised users. This will require an additional authentication function either through a simple service set identifier (SSID) password entry or through a more sophisticated authentication process requiring a dedicated authentication server and captive web portal where users are redirected to a landing page.

However, current public WiFi networks suffer from the inconvenience of manually typing the username/password to be authenticated before accessing the internet. This is especially true when typing onto a small smartphone screen. An emerging WiFi Standard, IEEE 802.11u, aims to simplify the authentication and authorisation process for WiFi access and will play a critical role in automating the login process for users connecting to WiFi networks.

For the automated login process to work, both the wireless device and the AP must support 802.11u.

For encryption to secure wireless links, the WiFi Protected Access II (WPA2) protocol is widely available for IEEE 802.11 implementations. It is the de facto standard for securing WiFi networks, however in order to allow easy connection, most public WiFi networks operate unsecured, instead relying on the end user or an application to secure any sensitive data. IEEE 802.11u may enable easier use of WPA2 encryption on public networks.

Alternatives to WPA2 for authentication and encryption to improve security for WiFi networks include:

a) IEEE 802.1X, which uses encryption and tunnelling, operating at the Ethernet layer;
b) The use of higher layer security (e.g. IPsec, which is subject to ongoing debate on whether or not to implement it);
c) The use of SIM level authentication; and,
d) Technology for ‘per device’ encryption, e.g. the use of a unique key based on the hardware’s MAC address.

Deployment

There are a number of key factors that must be considered when planning and deploying a WiFi network in order to ensure stability, ease of use and correct operation.

WiFi devices operate in the unlicensed public spectrum of 2.4GHz and 5GHz. When there are multiple WiFi networks deployed at a given location (e.g. in a shopping centre, stadium, etc) then in an ideal world, processes should be put in place to manage interference among the networks operated by carriers, site owners and retail outlets, all trying to use the same frequency bands.

The challenge in using the unlicensed public spectrum is the lack of control to shield from RF interference generated by private WiFi networks and other devices that use the same spectrum in the vicinity of the public network.

An intrusive WiFi AP such as this is called a ‘rogue AP’. A number of technologies also operate within the 2.4GHz and 5GHz channel space, including Bluetooth devices; DECT cordless telephones; AV in-home repeaters; garage door openers; wireless security systems; baby monitors; and smart meters, including ZigBee and WiFi mesh. It is expected that due to explosive growth in smartphones that use 2.4GHz spectrum, there will be heavy congestion experienced in the near future, forcing the widespread use of 5GHz spectrum or adapting smart antenna that actively mitigate interference.

Most advanced WiFi systems will use a wireless controller to manage multiple APs in a coordinated fashion to minimise overlap and interference. Further, there needs to be sufficient (unlicensed) spectrum for growth in WiFi usage.

Most advanced WiFi systems now have the ability to force clients to connect at the higher 5GHz spectrum instead of the 2.4GHz by default. This is becoming a common practice across major wireless vendors and provides a better experience for the users (if the 5GHz isn‘t congested already).