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No notes for slide. In light of the significant increase in demand for network capacity, network operators are asking themselves whether cost-effective microwave can scale up to meet the ever-growing capacity demand. The benefits of microwave as a transport technology are numerous and well known.
Microwave is scalable. It is quick and inexpensive to deploy. It is highly reliable. It does not suffer from extended cessations in service such as experienced due to fiber cable breaks. It is the preferred transport medium provided that it scales to fiber capacity. Inspired by, but inherently different from the well-known non-line-of-sight MIMO technology widely used in access networks, LoS MIMO revolutionizes microwave communication in terms of capacity and spectral efficiency.
Microwave Technologies that Increase Capacity There are numerous advanced microwave technologies that already enable operators to satisfy the growing demand for capacity. Since then, incremental improvements such as high modulation schemes QAM, QAM , packet compression, asymmetrical bandwidth delivery and Layer 1 link aggregation Multi-Carrier Adaptive Bandwidth Control techniques have been used to improve spectral efficiency and thus boost microwave capacity.
Originally a non-line-of-sight NLoS technology 2. Instead, LoS MIMO achieves spatial multiplexing by creating an artificial multi-path not caused by physical objects, but rather by deliberate separation of antennas in such way that a deterministic and constant orthogonal multi-path is created.
In order to keep things simple for 3. Spatial separation between antennas is denoted respectively, and the different signal path lengths are denoted for the length of the path between transmitter and receiver.
Separation between signals is achieved by having them arrive at a specific and constant phase difference at the different antennas. A signal processing algorithm is then applied to cancel cross- interference and to separate the signals. Control of the phase at which signals arrive is achieved through the length of the paths over which the signals traverse. The path length can be controlled by the distance of separation between antennas on each side of the link.
The following equation formulates the antenna separation distance required for optimal LoS MIMO operation: Equation 1 where denote the respective antenna separation distances on either side of the link in meters , denotes the overall link distance in meters , denotes the speed of light and denotes the link frequency in Hz.
Constraints which may limit antenna separation on one side of the link tower space, mechanical or wind load, etc. The following diagram gives an idea of the symmetrical separation needed between antennas for different link spans and in different frequencies: 4.
If a single stream of data is to be sent over the link, or if the customer wishes to protect the connection, then a networking device needs to perform some sort of link aggregation splitting the data stream between the two FibeAir IPC units.
It also demonstrates that the trade-off between antenna separation on both sides of the link yields a continuous line of optimal installation scenarios, and that sub-optimal antenna separation on one side can be offset by the separation on the opposite side. Figure 6 further demonstrates how sub-optimal antenna separation affects the capacity relative to an optimal installation.
Figure 6 -Effect of sub-optimal installation on capacity max. First, we must understand that antenna separation does not have to be a vertical separation.
On masts and poles, it is convenient to separate the antennas vertically, but horizontal separation e. Tower space, mechanical or other constraints may force installation of different-sized antennas for the MIMO link. If the aforementioned installation constraints force installation of a smaller antenna on one side of the link Figure 9-A , we can even out this link budget imbalance by either lowering Tx power on the paired MIMO transmitter Figure 9-B , or by reducing the size of the paired MIMO antenna as well Figure 9-C.
Multiplying capacity LoS MIMO enables transmission of two independent bitstreams over the same frequency and same polarization. Using both polarizations of a frequency channel, i. Immunity to dispersive fading Spatially separated antennas employed in MIMO can also provide the benefit of space- diversity link protection and result in higher immunity to dispersive fading than SISO links.
Improved system gain Combining received signals from both antennas boosts system gain by 3dB as noise is uncorrelated between receivers , similar to that achieved by space-diversity systems with IF-combining. Further improvement to system gain can be achieved at the expense of the capacity boost by splitting a bitstream between transmitters operating in MIMO, thus enabling reduction of modulation scheme and, in turn, increasing system gain both Tx power and Rx sensitivity.
This can help in achieving longer link distances, reduced antenna sizes, or spectrum decongestion by utilizing higher frequencies for long-distance links. An improvement of as much as 20dB can be achieved. Advanced microwave uses this technology in a LoS setup by installing multiple antennas with a calculated separation between them.
About Ceragon Networks Ltd. Ceragon Networks Ltd. Based on our extensive global experience, Ceragon delivers turnkey solutions that support service provider profitability at every stage of the network lifecycle enabling faster time to revenue, cost-effective operation and simple migration to all-IP networks.
As the demand for data pushes the need for ever-increasing capacity, Ceragon is committed to serve the market with unmatched technology and innovation, ensuring effective solutions for the evolving needs of the marketplace. Our solutions are deployed by more than service providers in over countries.
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Sign In Register. The Edge. Private Networks. White Papers. Comment 0. Under the agreement, Nokia will include Ceragon's high-capacity FibeAir family with its microwave radio product portfolio as Nokia PowerHopper Vario to provide complete cellular transmission networking solutions. This OEM agreement is the outcome of several years of successful integration of Ceragon's SDH radio products into Nokia's global transmission solutions.
Ceragon Microwave Radios
As the world's leading wireless backhaul specialist, Ceragon Networks ensures that mobile and fixed-line carriers, as well as private network operators have the transmission capacity to reliably deliver the voice and premium data services that we all rely on. From telecommunication operators to mobile service providers, everyone is after the backhaul capacity necessary to provide the latest services, expand into new markets and to simply meet the demands of their current networks. Ceragon solutions have been designed to eliminate bottlenecks with cost-effective, future-proof high-capacity backhaul connectivity while maintaining stellar performance. Known as the premier provider of short haul solutions, Ceragon's recent acquisition of Nera Networks extends the scope of solutions we provide. This unmatched reach that now includes long haul solutions allows our customers to expand their own offering. Agile and responsive, Ceragon addresses your evolving needs, so that you can fully leverage new opportunities.
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Transition your network to pack-based radio performance by deploying Ceragon FibeAir wireless backhaul products. You can scale affordably with this series of microwave radios that combines TDM with Ethernet functionality — it can support up to Mbps full-duplex throughput. Minimize your costs as you enhance your operations and strengthen network capabilities by integrating used Ceragon microwave radios. Worldwide Supply has a broad selection of FibeAir equipment with options to buy used Ceragon microwave radios. The FibeAir line is optimized for private network applications and has been deployed across municipalities, utility networks, public safety networks and business access applications.