Wireless local loop

Avaiability of WLL providers at your location



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Wireless Local Loop

Wireless local loop is a highly modern high-speed Internet connection with which the data is transmitted on the final stretch between the customer location and the backbone via a direct radio connection (“WLL” = Wireless Local Loop).

The service consists of the provision of the data connection and an end device (Customer Premises Equipment – “CPE” as a final unit for connection to the Internet including to and from the Internet or for connecting an IP-compatible customer network (“LAN”).

Advantages of WLL

Real media redundancy

In conjunction with a terrestrial back-up connection, you are equipped to combat any disrupting factors

Comfort leased line

  • 99% service availability
  • Communicated, instantly implemented bandwidth
  • Fast and uncomplicated option to upgrade to higher bandwidths

Flexibility due to modularity

Back-up-ready: can be quickly expanded by different back-up connections for real-time media redundancy without complications.

Internet Services via Wireless Local Loop (Wireless Local Loop (WLL))

Internet services via wireless local loop are ideal for companies that

  • have high demands on very high bandwidths
  • do not have a fiber glass connection in the building
  • desire high availabilities
  • place special value on media redundancy
  • require quick implementation and provision of high bandwidths

WLL is the alternative to classical internet connections using copper or fiber glass infrastructures. It is particularly suitable as a cost-effective primary line for remote sites, but can also be used as an effective back-up with its own infrastructure.

WLL is a flexible, secure and fast data connection option which is an ideal basis for both a high-quality Internet connection as well as Internet-based VPN (Virtual Private Network) or telephony.

How wireless local loop connections work

Wireless local loop connections to the respective backbone of the Internet service provider (ISP) is established via a so-called air interface. Wireless local loop offers scalable bandwidths with up to 800 Mbit/s on the upstream and downstream.

The following components are required to establish a wireless local loop connection:

  • a wireless local loop system that is set up at the customer location, a permit to do so by means of a building owner declaration (BOD), a wireless local loop system at the nearby carrier base station, an inspection of the visual connection between these two locations (line of sight check), an inspection of the customer premises during which the structural aspects are inspected or defined, and a licensed radio frequency from the BNetzA (Federal Network Agency).
  • Provision or installation and operation of all components, except for the BOD (and potentially necessary in-house cabling), which shall be provided by the customer, shall be handled by the wireless local loop provider.

The wireless local loop system consists of a wireless local loop antenna, an outdoor unit (ODU), an indoor unit (IDU), the necessary connection cables incl. installation materials and remains the property of the wireless local loop provider. The IDU is connected to the corresponding carrier router and the Internet service is provided to the customer via wireless local loop.

Requirements at the customer’s site for a wireless local loop connection

  • Maximal 30 km distance to the next wireless local loop location
  • Line of sight between the customer location and the wireless local loop location
  • Permit to install the wireless local loop system and the corresponding work on the building by means of a building owner declaration (BOD)
  • Building-related requirements (statics, etc.) that make the installation of a wireless local loop system possible.
  • If additional work is required for the installation of the wireless local loop system, the additional costs shall be borne by the customer or the customer must perform the work or have it performed. For instance, at the router installation location, the customer shall provide sufficient in-house cabling and a sufficient power supply.

Alternatives to a wireless local loop connection

If the necessary infrastructure (via copper or fiber glass) for the desired bandwidth is not available at the customer site, or it cannot be established without very high investment costs, there is no real alternative to wireless local loop-based Internet connections other than cellular data (UMTS/LTE) and satellite-based Internet connections, which aren’t really an alternative.

*the information regarding the max. achievable bandwidths may differ depending on the provider!

Overview of all providers

Provider Product
Vodafone Vodafone Internet Connect basic (WLL)
qsc QSC-WLL business
interoute Interoute – directional radio (WLL)
Avaya Avaya Eco Internet (WLL direct connection)


  • In a Wireless-Local-Loop, the path from the roof position of a base station to the end customer’s location is bridged via a radio field, e.g. using a frequency of 26 GHz.
  • The antenna at the roof position at the customer’s location must have an uninterrupted line of sight with the base station.
  • An antenna with a transmitter/receiver unit, the outdoor unit (ODU) is mounted on the roof at the end customer’s location.
  • The end customer connects its network to an interface on the indoor unit (IDU). The ODU and IDU are connected via a cable.

General process

Internet services via directional radio are commissioned in stages:

  1. Review of the general availability
  2. Capacity/bandwidth query at the regional network planning agency
  3. Signing the contract, obtaining the BOD and commissioning order
  4. Commissioning the line of sight check
  5. Site inspection to clarify the structural measures
  6. Applying for the wireless local loop frequencies from the BNetzA (Federal Network Agency)

Line of Sight (LOS check)

  • Line-of-Sight (LOS) means that the antennas at the respective end points of a radio path can “see” each other.
  • LOS connections are usually implemented in systems with high data rate, availability and range of path requirements. Wireless local loop paths are always LOS.
  • LOS must be checked for each individual section on site.

Environmental impacts on wireless local loop (WLL) connections

Radio systems are subject to environmental influences which don’t play a role with fiber glass or copper networks:

  • Rain insulation: in the event of heavy rains which can arise in conjunction with storm fronts, the transmission rate of the radio path can be reduced.
  • Wind loads on the antennae can lead to misalignment, in particular on wireless local loop paths.  properly built roof constructions, the wind load generally doesn’t play a role.

The systems used are capable of increasing the availability of the transmission path using automatic and uninterrupted modulation changes: in the event of bad weather conditions, the system will be switched to a less sensitive modulation.


In turn, radio systems are not affected by typical error and failure sources in the grid network:

  • Cable breakage due to underground construction.
  • Reduced transmission rates due to crosstalk between unshielded dual copper wires.
  • In practice, radio systems can achieve availabilities comparable to those of fiber glass or copper networks.

Interception protection

Wireless local loop connections

In order to intercept a wireless local loop connection (transmitter/receiver direction), first the complicated interception technology would have to be positioned near the direct line of sight between the base station and the customer antenna and could therefore be quickly located.

The right frequency – inaccessible to third parties

In order to intercept a radio link, the attackers have to know the frequency bands assigned by the Internet service provider and the frequencies used for the link since there are hundreds of different frequency channels in the same geographic area. The technology used is still based on a digital transmission that makes interception difficult in principle due to the digital data stream. Furthermore, the special wireless local loop technology is very expensive and is only available from a few manufacturers.

Combined procedure for proper operation

The “customer – base station” and “base station – customer” connections are established using a variety of combined modulation and demodulation procedures. This digital procedure converts or encrypts the data so the transmitter and corresponding receiver can work properly (equation, carrier recovery and timing recovery).

Digital data packets – secure transmission

The FEC (Forward Error Correction) encoder in the multiplexer and demultiplexer is applied to the already existing data and ensures the digital data is securely evaluated later. The data is sent to the separation process during which the bytes from the service channel and that of the data are processed separately. This means an attacker would have to sort the desired data packets out of the radio traffic in the wireless local loop field. In order to generate the transmitted bit stream from the received radio signals, the proprietary modulation of the provider-specific technology must also be known.

Air instead of earth – Optimum transmission

Restoring the original information from an intercepted data stream is de facto impossible without precise knowledge of the aforementioned security measures implemented by the WLL provider. The security of the transmitted data is thus significantly higher than with conventional, cable-based transmissions. These connections largely utilize standardized and thus commonly known transmission methods for which the technology is installed on the ground floor of the customer’s building. The radio technologies used are installed on the roofs. On the one hand, these are not accessible to everyone and on the other, they are installed in locked system cabinets. The data is also forwarded via directional radio or fiber glass until the signal has been introduced to the backbone of the Internet service provider (ISP).

Wireless local loop connection variants
WLL Internet connection (simple)  WLL-Variante-1
WLL Internet connection with back-up line based on a LeasedLine via PDH/SDH or Ethernet via SDH  WLL-Variante-2
WLL Internet connection with back-up line based on a LeasedLine via Ethernet FirstMile  WLL-Variante-3
WLL Internet connection with back-up line based on a LeasedLine via SDSL/SHDSL.bis  WLL-Variante-4


Ronald Bals
ICT Expert

Tel: 089 / 219 914 810
E-Mail: datendienste@savecall.de

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