Hotspot (Wi-Fi)

Hot spots are public wireless Internet access points (often paid) are available to everyone. Most are installed in public spaces: in restaurants, coffee shops, libraries, hotels, hospitals and public places (airports, railway stations, etc.). With a notebook, PDA or mobile phone can connect to the Internet using the wireless technology.

As an open WLAN ( OWLAN ) is called a public hot spot, the operator shall provide it for other users is available without charge for use.

Construction of a hot-spot system

The job of a hot spot is to allow users easy access to the Internet and for that perform the required activation of the user. For more components and functions are required:

• Wi-Fi access points, which with their wireless devices initially, allowing users to access the local network.
• An interface between this WLAN and the Internet. At this place - usually a router - a review instead of who is allowed to access the Internet. The system recognizes when accessing the Internet, if a user is already logged on. The distinction of the user - respectively the computer - is done via IP addresses or MAC addresses.
• In the event that a user is not registered, its web browser is first automatically redirected to a login page. There, you can authenticate yourself by entering a code or password. The entered code is based on a database that is located on the Internet or locally on a hot-spot router, checked and the user unlocked. Each code has a certain predefined time credit ( prepaid method ).
• The application activates a timer in the hot-spot router, which ensures that access ends after the booked time and is blocked. In almost all systems, the user can interrupt the Internet session in the meantime. He logs off, he can use his unused time credit later on. Some systems also provide automatic storage of the credit if the user forgets to log out.

Distinction to the normal Wireless Access Point

Unlike normal wireless access point is usually not desired communication between the participants at the hot spot, as this security problems might occur. In Hot Spots user isolation is therefore usually configured. Refers to data that are directed to another user of the same hot spot, not forwarded and thus prevented the mutual access to network services devices from other users.

However, the user isolation offers no protection against eavesdropping own data because they can be received directly from other users with so-called sniffer programs. In a hot spot of access to the internet is usually unencrypted, or key known to a wider circle of users. Therefore, data are relatively easy to read. Is particularly in the transmission of access is a risk that this will go unnoticed tapping and abused later. The login page of the hot spot (if any) is secured for this reason usually over a TLS connection and issues a certificate available. Even with all other logins each user should pay attention to this relatively public nature of hot spots and eighth in a special measure on a secure connection.

Differences of individual providers

Some manufacturers use a code instead of a username and password. To obtain a valid access in some cases, a cell phone ( of a certain provider ) or a credit card is required. Often, the access can be purchased locally simple.

The management of hot spots include the storage of credit. In principle there are two possibilities:

• If this data is stored locally and remotely, go the credit ( also partly used ) with a system reboot usually lost. Also, roaming, that is, the use of an access in different locations, then not possible.
• If the data is stored in one place, the additions of several hot spots are queried. In this way, hotel chains, for example, offer their guests access, which can be used in all connected hot spots.

Differences internal / external roaming

• Internal Roaming ( 1): The mobile station moves from one access point to another access point within a home network because the signal strength is too weak. An authentication server ( RADIUS) assumes the re- authentication of the mobile station via IEEE 802.1X. The billing of QoS is done in the home network.
• External Roaming ( 2): The mobile station (client ) changes in a "foreign " WLAN and takes their defined services. The user can thus use independently of his home network to another foreign network, if this is open to visitors. These special authentication and billing systems are required, the charge clearly the mobile users services while abroad.

Remuneration

Depending on the desired scenario, a hot spot for the user can be charged (usually organized in hot-spot communities, see below) or the operator collects a user fee for use.

Prices have greatly cheapened since 2003 and now established in a span of two to eight euros per hour. Credit cards that allow even repeated logging on and off, are increasingly common.

You can select each under two different payment methods in the paid hotspot providers:

Subscription in advance

It must be on the provider's website in advance ( from home, from work ) sign and buys a subscription ( monthly free volume or free hours).

On-site payment

It will connect to a hot spot and paid through an intranet site for a certain period of time ( pre-paid method ) by debiting a customer account ( for identification ), by credit card, Paypal or - more rarely - by debit card or coins. The so-called post-paid user process can only surf and the provider bills later, the unused time off. The latter method has proved to be impractical because the cost transparency for the user disappears. Technically, it is an established connection to the hotspot, intercepted the requested page and instead called a portal page delivered to the client ( redirect). On this page the tariff information shall be displayed and optionally the necessary payment information. If the payment completed, will be automatically forwarded to its original destination.

For users who frequently surf spots available, the subscription in advance is the better alternative, while for irregular and rare use of the on-site payment can be more useful.

Billing system (User - fairness model)

The dynamic pricing model enables a volume - based billing, with only the corresponding payload (data, video, audio ) will be charged. Furthermore, the tariff is classified according to network load and traffic classes ( user needs).

When the network load increases, then the user must pay the next higher tariff class. The user is asked if he wants to maintain the session even at a higher rate still. Furthermore, in time-critical applications (video, audio ) a higher class fare will be charged than for non - time-critical applications (such as reading Web pages, e- mail).

The "User - fairness model" is technically realized by EDCF (IEEE 802.11e). A EDCF user priority list shares the traffic in three access categories (access categories ) and user preferences (user Priorities, UP) a:

• Data [ UP 0 | 2]
• Video [ UP 5 | 4]
• Audio [ UP 7 | 6]

If the network utilization increases, then the frames of each access category is a lower priority value assigned - as if the data transfer is not time-critical.

Hot spot technology

For registration and data transfer most of IEEE-802.11b/g-Standard used. The registration at the hot spot is almost always encrypted ( SSL ). After data is typically sent unencrypted, unless it is used VPN. However, this requires a VPN client installation on the customer laptop.

There are two payment methods:

• Central billing via Internet: The hot-spot provider enables the accounting of a back-end service, with redundant hardware and global data for multiple hot-spot operators. That is, a customer can surf with the same data in multiple locations (eg, German Telekom and Swisscom).
• Local Settlement: The hot-spot provider, who is also the owner, makes even the billing and tariffs. The prices are usually cheaper, sometimes even free.

Roaming

From roaming we speak, similar to the mobile when a customer of a (commercial) hot-spot operator uses the hot spot of a foreign operator in the country or abroad. Here he can log in with the login information of its home service provider and get out of this his bill. In Germany, translated especially the independent WLAN operator roaming, thus allowing about The Cloud for some time to business customers of O2 access to its own network. In contrast, for example, is not yet possible to roam between the networks of T -Mobile and Vodafone at the moment.

Hotzones

Fusing multiple hot spots together, it is called hot zones. Manufacturers have developed different technologies here, but most are incompatible with each other. Approaches to develop standards for the merger of hot spots, it has indeed given (eg, Green Spot, WISPr ), not recently, though not very successful due to the commercial nature of many hot spots.

Portable Wi-Fi Hotspot

A mobile Wi-Fi hotspot ( also referred to as " MIFI " ) is used for one or more terminals - without their own GSM module - as a data bridge in a cellular network. Devices such as the Apple iPod ( with no cellular reception part ) so can still use mobile Internet. It also remains the user, since it leads the hotspot in the vehicle or in his bag with him, as in the mobile network in his freedom of movement unaffected. This technique is abroad using an appropriate host country providers sim card especially for bypassing an otherwise expensive roaming fee. The phone access using the familiar phone number remains the same. For the power supply by a built- in battery Hot Spot, for the hotspot Internet access is ever a mobile phone contract ( prepaid to mobile phone contract ) is required.

Quality characteristics

Hot spots, within the meaning of settled or free wireless access to the Internet, distinguished by the following qualities:

• The authorization of users before access is released to the Internet.
• Wi-Fi access and Internet, users need to change network settings without.
• The protection of the users themselves. In contrast, standard access points, where an exchange of data is desired.
• The billing or collecting time and / or volume quotas ( in seconds and byte for byte, audit-compliant).
• Access Point roaming, the smooth relocation site of the connected access point.
• In commercial hot spots usually not offered: traffic encryption with WPA ( WEP is outdated and is no longer considered safe). Otherwise, only encrypted applications such as HTTPS ( SSL encryption) are recommended. As an alternative to EPA, the entire traffic will be encrypted with about OpenVPN SSL. The best security feature hotspots because there, in contrast to the unencrypted and PSK ( preshared key) networks, the data of each user are encrypted with his personal password with WPA-Enterprise encryption. In the case of a second unencrypted SSID is usually so requires the user to register themselves and can get the personal login at all.
• The protection of user connections via WLAN or LAN through a VPN connection to the Internet gateway of the provider.
• The number of supported languages ​​on the login or registration page.
• Accessibility, the active involvement of elderly and disabled people on the login or registration page.
• The number of billing methods ( prepaid, postpaid and electronic money ).
• The possibility of free roaming ticket ( intersite validity of access codes ).
• The free roaming with other hot-spot operators in compliance with quotas (elimination of the clearing house ).
• In selbstgemanagten systems: the retention of the previously -defined ticket price to 100 percent without Provisonsabgabe.

Hot spots as a tool for customer retention and distribution

In the United States and Canada, the coffee shop chain Starbucks offers its customers since the summer of 2010 free, unlimited access to their hot spots. It took in October 2010 according to the company every month more than 30 million customers.

Since October 2010, Starbucks operates a "digital media network ": customers who log in with their laptop or smartphone in hotspot obtained on a menu page music, videos, news, jobs as well as digital books to choose from. The book is to offer change daily. The e-books can be read in a browser for free, as long as the customer is logged in the store. The news provides, among other things, the three major American newspapers New York Times, Wall Street Journal and USA Today. Jobs and career advice provided by the Internet network Linkedin. The sale of literature, music and videos wrapped cooperation partners from Apple about his iTunes Store. Once a week ( every Tuesday ), you can download a free song.

The Mayor of London had announced during the 2012 Summer Olympics, to cover the entire city with hot spots to provide a smooth Internet access available to tourists.

In Germany you will find public hotspots in restaurants of fast food chains McDonald 's, Burger King, Starbucks and Pizza Hut. The German rail cooperates with Deutsche Telekom and allows 30 minutes free access to several main stations. The company Wall AG in Dusseldorf created the first time a city-wide network permanently with 50 free hotspots, which are integrated into outdoor advertising.