DAS solutions

Distributed Antenna Systems (DAS) are needed to provide stable mobile communications at various sites and territories. Unlike less technologically advanced counterparts, they allow you to use several communication standards at once, from classic GSM to high-speed LTE.

The main feature of the DAS solutions is the increased signal power over all supported bands, which contributes not only to the stability of the connection but also to the coverage of the maximum possible area. In addition, such systems are much easier to install, and spending on the placement of feeder lines is minimised.

How DAS Works

Unlike other communication complexes, in DAS the source of signal propagation is not its generator, the task of the complex is to amplify it and further retransmit it for reliable reception on subscriber devices. One of two methods is used to propagate the signal:

  1. Receiving a signal from an antenna fixed on the facade of the serviced object
  2. Signalling from the local baseline of the mobile operator, BTS.

When forming a DAS, it is necessary to fix antennas on roof structures or elements of the facade of the serviced building, each of which receives a signal coming from the mobile operator’s base station in a certain range. This signal is fed to an amplifier. As a rule, a wired connection through a coaxial line is used.

The main amplifier unit transforms the high-frequency signal into an optical form and broadcasts it through an optical fibre to a remote unit, where the reverse transformation takes place. The optical signal again becomes high-frequency, which allows efficient transmission through antenna-feeder networks.

To monitor the operation of DAS, it is permissible to use remote schemes based on the use of modems operating in GSM, 3G, and LTE networks.

Distributed antenna systems fall into three main categories:

  1. Passive. The signal is transmitted via a coaxial cable to each level of the serviced object. When forming the structure, passive components, dividers, splitters, and couplers are used. There are no active electronics, so for good communication quality, it is necessary to carry out accurate preliminary calculations so that the initial power reserve is sufficient.
  2. Active. The active DAS operation algorithm is described in more detail above; it is based on the transformation of an incoming high-frequency signal into an optical form.
  3. Hybrid. A competent combination of the features of the systems described above makes it possible to reduce the cost of implementing the complex without harming its efficiency, stability, and reliability. The hybrid structure means that with the help of passive components, several antennas are connected to the remote unit at once. Such units, which convert the signal from digital to analog, are placed at the required levels, and floors of the object, thanks to which it will be possible to form a coaxial network connecting the antennas.

Advantages of DAS

The main strengths of distributed antenna systems are as follows:

  1. Scale. The complexes are fully suitable even for large facilities, multi-story buildings. The length of the fibre optic line used to transmit the signal between the head and remote units is tens of kilometres. At the same time, even with a huge DAS scale, it is possible to eliminate possible problems with signal strength and limit the speed. All current standards are supported, up to LTE +, 4G.
  2. Unification. Within one DAS system, you can combine equipment from different manufacturers, which simplifies implementation, reduces the costs associated with it, and allows you to create a complex based on existing devices by adding new modules.
  3. Profitability. One head module can serve several remote ones at once, which reduces the cost of purchasing and installing equipment.
  4. Ease of control. You can monitor all system parameters, and adjust and configure them remotely using modems.
  5. Ease of installation. Due to their compactness and low weight, DAS components are easily fixed to most support structures without pre-strengthening, strengthening the base.
  6. Scalability. If necessary, the DAS system can be expanded, the network coverage area can be increased, and new remote modules can be added.

Preservation of the aesthetic appeal of the object, the urban architectural environment, and the elimination of problems with various municipal and administrative departments. It is far from always possible to obtain permission to build another cell tower, in some areas a complete ban has been imposed on this. The components of the DAS complexes are much more compact, their installation does not cause complaints and claims and is not associated with fines. Even upon close examination, the devices are difficult to distinguish on facades, lighting poles, and other structures.

Areas of Application For DAS Systems

DAS solutions are ideal for various public spaces, and social, commercial, and administrative facilities with high traffic, from airports and hospitals to shopping and entertainment centres, and stadiums. The complex ensures communication stability even during periods of maximum fullness. For example, at the stadium, when tens of thousands of fans gather in the stands. The capacity of one cell tower is not enough to ensure that each subscriber can effectively use communication services.

DAS systems are also an ideal solution for modern buildings with façade glazing systems that use low-emission glass to provide comfortable microclimatic conditions and reduce the load on heaters and air conditioners. Sputtering on such glasses is a serious obstacle not only for thermal energy but also for the cellular signal, its power drops to minimal values, sometimes insufficient even for ordinary voice calls. DAS antennas located inside the object help to cope with the problem.

Final Thoughts

The use of distributed antenna systems improves performance, improves signal quality, increases network capacity, and ensures more efficient use of energy. The DAS system is used in the famous Hilton hotel in Las Vegas. It supports the most modern cellular networks, MIMO technology. DAS solutions are an attractive choice for a variety of communications scenarios, including mobile networks, wireless LANs, and industrial communications systems. If you want to install DAS solutions to grow your business and provide customers and employees with a stable connection, we recommend that you contact UCtel, which has vast experience in installing DAS solutions.