HK1165927B - Vault antenna for wlan or cellular application - Google Patents

Abstract

A fringe-effect vault antenna includes a communications vault having a non-conductive cover disposed substantially at ground level. An antenna element is positioned in the communications vault. A metallic reflector has an edge, positioned substantially parallel to the ground, where the metallic reflector and the edge are configured to cause an edge diffraction, or "fringe-effect" upon the RF fields of the antenna to cause those RF fields to diffract in a direction toward the ground.

Description

Vault antenna for WLAN or cellular applications

Technical Field

The present invention provides an innovative antenna system for underground vaults. It provides a means to achieve the desired elevation range while meeting the important requirements of the ground azimuth range. In addressing the technical problems associated with underground vaults, it also proposes a method of mass producing low cost antenna solutions for widespread deployment of microcells (microcells).

Background

Ground vaults are widely used by service providers, such as cable television providers or telephone providers, to access equipment and cables buried in the ground. These vaults are typically located flush with the ground and extend throughout the metropolitan area where the cable or telecommunications equipment is located.

With the popularity of Wireless Local Area Networks (WLANs), there is an increasing need to find a cost-effective way to deploy access points with the various "assets" available to service providers. One core asset that many service providers have in large numbers is the underground vault.

The present invention provides a method of providing repeatable and optimized Radio Frequency (RF) coverage using a dome as a radiating element source. It is well known in the art that good RF coverage is often dependent on antennas being mounted at higher elevation angles, such as on poles or roofs. Most cities have hundreds or thousands of cell towers or rooftop "macro-cells" (macrocells) consisting of 40W high power transmitters per radio channel with large high gain antennas. These macro cells provide cell coverage of hundreds to thousands of meters. Many of the radio propagation models disclosed detail the empirical tradeoff of antenna height for cellular coverage. This is a well-known and documented science.

As cellular revolution progresses and cellular users increase, more cost effective low power (i.e., up to 4W) base stations have been introduced to provide smaller cellular coverage areas of hundreds of meters. Mounting equipment on light poles and street assets such as billboards or building walls has become a cost effective way to implement cellular underlay networks that offload the capacity of macrocellular networks. Cell coverage areas of less than a few hundred meters are not considered, partly because of the high cost of microcells and also because of the high rental cost of installing assets.

With the introduction of "pico-cell" and "nano-cell", the cellular revolution is continuously progressing; however, neither type of base station is used in any obvious way for outdoor cellular coverage. Picocell base stations have not found practical use in the industry, while nano-cellular base stations have successfully found a large market penetration for residential indoor applications.

WLAN systems have emerged as a breakthrough technology for cellular systems. WLAN systems employ unlicensed spectrum and provide data throughput levels two orders of magnitude higher than commercially deployed cellular systems. WLAN systems also have low transmit power (i.e., typically less than 4W EIRP (effective omni-directional radiated power)), operate in uncontrolled unlicensed spectrum and cannot be easily deployed with rooftop macro cells or cell towers. Outdoor WLAN systems are generally deployed by connecting WLAN transceivers to street light poles or processing these transceivers on cable installations in the same way as cable amplifiers or DSL (digital subscriber line) repeaters are deployed and powered. These WLAN systems typically provide a coverage radius of several hundred meters. Smaller cells have been deployed in certain locations, such as starbucks or mcdonald. These coverage areas are very small, ranging from tens of meters to a hundred meters in radius, but such coverage is cost effective due to the low equipment cost of WLAN transceivers.

Many locations have been found that do not have above-ground assets to place WLAN transceivers. These sites include communities without antenna devices, above ground power supplies or communication poles. In some areas, poles may be present, but municipal regulations, as a rule to minimize visible clutter, prohibit the deployment of equipment on poles. In all these areas, the same traffic can be carried generally, but it is buried and carried by underground pipes, only available at the base, at the metal service cabinets or at the ground vault level. Accordingly, the present invention overcomes this drawback.

Disclosure of Invention

In one aspect, the present invention provides an edge effect vault antenna. The antenna includes: at least one antenna element located in an underground vault, the vault having a non-conductive vault cover; an antenna frame; and a metal reflector having a metal edge, the edge disposed substantially parallel to the ground, the metal reflector configured to produce an edge effect on the received radio frequency signal and direct the received radio frequency signal towards the at least one antenna element.

The non-conductive dome may comprise a material selected from the group consisting of concrete, concrete polymers, and plastics. The antenna mount may be connected to the dome. Alternatively, the antenna mount may be supported by a structure of the vault. The edge effect vault antenna may further include a tilt bracket configured to direct these received radio frequency signals further toward the metal reflector.

The edge effect dome antenna may further include a tilt structure that tilts an elevation angle of the antenna so that a main beam of a received radio frequency signal is disposed toward an edge of the dome cover. The fringe-effect vault antenna may further include an azimuth tilt structure to tilt an azimuth of the antenna. The fringe-effect vault antenna may further include a diffractive antenna mount and an adjustment structure configured to adjust an elevation or a slope of the diffractive antenna mount so as to be able to direct a main beam of the antenna. The fringe-effect vault antenna may further include a mounting bracket that enables the antenna to be mounted longitudinally or transversely so that the directivity of the antenna may be disposed toward either side of the vault. The fringe-effect vault antenna may further include a bell jar coupled to the vault cover, the bell jar configured to retain an air pocket around the at least one antenna element.

The fringe-effect vault antenna may be selected from the group consisting of an omnidirectional fringe-effect vault antenna, a directional fringe-effect vault antenna, a parabolic fringe-effect vault antenna, and a corner-reflection fringe-effect vault antenna.

In another aspect, the present invention provides a vault antenna system. The system comprises: at least one antenna element; an arched top cover; a deflection plate; and a radio frequency cable. The at least one antenna element, the deflector plate, and the radio frequency cable are integrated together in the dome. The radio frequency cable is configured to couple energy of a received radio frequency signal into the at least one antenna element.

In yet another aspect, the present invention provides a system for providing WLAN or cellular radio coverage. The system comprises: at least one wireless transceiver; a wired connection device; and edge effect vault antennas. The antenna includes: at least one antenna element located in an underground vault, the vault having a non-conductive vault cover; an antenna frame; and a metal reflector having a metal edge, the edge disposed substantially parallel to the ground, the metal reflector configured to produce an edge effect on the received radio frequency signal and direct the received radio frequency signal towards the at least one antenna element.

The wired connection device may be selected from the group consisting of DOCSIS, DSL, ADSL, HDSL, VDSL, T1, and E1. The at least one antenna element may be configured to allow wideband, multi-carrier operation. The at least one wireless transceiver may include a plurality of wireless transceivers, and the at least one antenna element may include a plurality of antenna elements, each of the plurality of antenna elements corresponding to a different one of the plurality of wireless transceivers.

Drawings

Figure 1 shows several dome antenna positions for simulation;

FIG. 2 is a graph of simulated vault antenna gain for the position shown in FIG. 1;

FIG. 3 shows several dome antenna angles used for simulation;

FIG. 4 is a graph of simulated vault antenna gain for the angle shown in FIG. 3;

FIG. 5 illustrates several dome antenna positions and metal reflectors creating an edge effect for simulation according to a preferred embodiment of the present invention;

FIG. 6 is a graph of simulated dome antenna gain and fringe effects for the position shown in FIG. 5;

FIG. 7 illustrates a dome antenna configuration with a flat metal plate used as a reflector to create edge effects in accordance with a preferred embodiment of the present invention;

FIG. 8 is a graph of simulated vault antenna gain for the antenna configuration shown in FIG. 7;

FIG. 9 shows several dome antenna tilt configurations for simulation;

FIG. 10 shows a dome;

figure 11 shows the dome of figure 10 with the cover removed to expose the omnidirectional dome antenna;

figure 12 shows an omni-directional dome antenna according to a preferred embodiment of the present invention;

FIG. 13 shows a dome;

FIG. 14 shows the dome of FIG. 13 with the cover removed to expose the directional dome antenna in accordance with a preferred embodiment of the present invention;

fig. 15 is a perspective view of a longitudinally oriented dome antenna in accordance with a preferred embodiment of the present invention;

fig. 16 is a cross-sectional view of a longitudinally oriented dome antenna in accordance with a preferred embodiment of the present invention;

fig. 17 is a perspective view of a transversely oriented dome antenna in accordance with a preferred embodiment of the present invention;

fig. 18 is a cross-sectional view of a transversely oriented dome antenna in accordance with a preferred embodiment of the present invention;

FIG. 19 is a perspective view of the dome;

FIG. 20 is a perspective view of the dome of FIG. 19 with the cover removed to expose the directional dome antenna in accordance with a preferred embodiment of the present invention;

fig. 21 is a perspective view of the directional vault antenna of fig. 20 according to the preferred embodiment of the invention;

fig. 22 is a cross-sectional view of the directional vault antenna of fig. 20 according to a preferred embodiment of the invention;

fig. 23 is a cross-sectional view of a transversely oriented dome antenna having a deflector with a parabolic and corner reflector profile.

Detailed Description

WLAN solutions have been deployed within above ground pedestals and in above ground cabinets. These solutions maximize cell coverage, and rely on ground clutter to achieve the range of 150-. Advanced multiple input-multiple output (MIMO) radio features (features) and antennas can extend this coverage, and redundant deployment is an important means for ensuring that clients using these systems are substantially unaffected by terrestrial propagation obstacles.

The present invention proposes specific aspects of the ground vault as a means of providing WLAN coverage. These vaults have not been commonly used in the outdoor coverage cellular industry and thus no literature or technology is available to study for optimal radio or antenna solutions. A key issue associated with the use of a ground vault is the ability to provide ground coverage, i.e., acceptable antenna gain along the street, so that pedestrians and local businesses can learn radio coverage from the vault.

To address this problem, various antenna solutions that can be easily deployed in a vault have been simulated using simulation tools, with the goal of achieving a coverage radius of street coverage of greater than 100 meters from a single vault, so that a particular site can be covered in a cost-effective manner with a few wireless transceivers. In a preferred embodiment, these transceivers are connected to the Internet using a DOCSIS 2.0 backhaul, and are 40-90VAC powered devices supplied through the cable service provider's main feeder network. However, in alternative embodiments, the system may employ DOCSIS 3.0, DSL, VDSL, HDSL or other means of connection to the internet, and may employ a standard ac power supply such as 100-.

All simulations indicate poor gain for ground vault deployment on streets. For example, referring to fig. 1 and 2, when an 8dBi antenna 12 is located in a below ground vault 14 with a plastic cover 6, the antenna 12 provides poor gain at ground (at an angle of-90 degrees), ranging from 0dBi to lower, even when located at different locations. These simulation results were consistent with early field measurements showing poor RF coverage when the antenna was placed inside the vault. These field results show a range of 50 meters with the best case of poorly controlled azimuth mode. In all of these cases, the RF range is set at the client device at the-75 dBm threshold.

Various other simulations were also performed. In these other simulations, the vault antenna system is different in some respects, for example, with reference to fig. 3 and 4, the position and angle of the antenna 12, and the changing of the gain of the antenna 12 are different in order to increase the gain of the vault antenna system. However, none have been entirely successful. In all these cases, the gain of the aerial antenna 12 is good, but the gain along the street is very different and often very poor. Furthermore, detailed simulations for studying charge current have demonstrated that none of the simulations show an acceptable current at ground that will achieve the desired results for a high gain antenna on the street.

In outdoor deployments, the RF signal may "edge" diffract around the building. In electromagnetic wave propagation, edge diffraction (or knife edge effect) is a type of redirection that exploits the diffraction of a portion of the incident radiation that strikes a clearly discernable obstruction. The knife edge effect is explained according to the huygens-fresnel principle, which states that clearly discernable obstacles to electromagnetic waves are used as secondary sources and produce new wave fronts. The new wavefront propagates into the geometrically shaded area of the obstruction. The term "edge effect" is used herein to describe edge diffraction or knife edge effect.

The inventors have also modeled and simulated the "fringe effect" applied to the design of a dome antenna, i.e., the metal fringe that "diffracts" the radio signal from the antenna towards the ground. The preliminary results are quite satisfactory, showing consistent and repeatable antenna gain along the horizon/street. These results are shown in fig. 5 and 6, in which the antenna 12 is shown facing a curved metal plate 20 for producing an edge effect. Fig. 6 highlights the region of acceptable street gain. It can be seen that the gain is consistent and repeatable.

Other simulations have been performed to test the variation of the metal edge and also to test the orientation of the antenna to determine the optimum edge effect antenna design for the dome. Referring to fig. 7 and 8, the results of these other simulations have been quite satisfactory, with up to 12dBi gain along the horizon, with good azimuth coverage starting from an 8dBi antenna.

Further simulations have been performed to attempt to optimize the antenna tilt and corresponding position in the dome antenna mount to determine the optimum tilt. Referring to fig. 9, three antenna tilt conditions are shown, but a number of variations have been verified.

In this manner, the inventive antenna system according to the preferred embodiment of the present invention was designed and field tested to verify functional operation. The following description illustrates the important edge effects utilized and the manner in which the edge effects are incorporated into the dome antenna in accordance with the preferred embodiment of the present invention. Furthermore, the present invention provides important aspects of the fringe-effect vault antenna, including details of the mounting brackets, such as the respective positions and tilt angles of the antenna elements. Protective measures to ensure proper operation of the dome antenna in inclement weather conditions that can cause the dome to be flooded are also described herein. The invention may be implemented using different types of domes available from different manufacturers, such as plastic domes from pentell corporation or concrete domes from NewBasis corporation. Possible (potential) variations of the dome antenna are also described herein, which allow for different orientations of the dome and different directional and omnidirectional antenna solutions for coverage. Elevation directional antennas suitable for use in building coverings are also disclosed herein. MIMO vault antennas are also disclosed herein.

With the continued development of the wireless industry towards smaller cells, which utilizes the widely available vault assets, vaults are expected to become important not only for WLAN-IEEE 802.11bgn and IEEE 802.11an coverage, but also for next generation cellular systems such as IEEE 802.16e, LTE (long term evolution), or other similar cellular standards.

Preferred embodiments of the dome antenna according to the invention are of at least two kinds: omni-directional dome antennas and directional dome antennas. Both of these preferred embodiments are for street covering, although the directional dome antenna has many variations that allow for high building covering as well as street covering. The description of these two embodiments follows. Alternative embodiments of the invention include parabolic and corner reflector dome antennas that are similar to directional dome antennas but for which the deflector mount is parabolic or V-shaped as a corner reflector. Fig. 23 shows how the deflector metal is shaped as a cross section of a corner or parabolic reflector. The antenna 36 is directed towards a deflecting reflector 42, the radiation field of which is subsequently reflected towards the edge 26. It is an object of these alternative embodiments of the present invention to achieve high gain directional coverage of high buildings by directing parabolic or corner reflector antennas with one or more antenna elements (for MIMO) towards the upper floors of the building while achieving ground edge effect coverage of street coverage. Most vaults will be at least partially below the ground (with the dome cover slightly below the ground), with other implementations contemplated where the dome cover is at or slightly above the ground. All of these implementations are referred to as "substantially at the surface".

In a preferred embodiment of the invention, the required edge effects can be optimized by ensuring that the metal edges completely cover the entire beamwidth for the signal aspect of the received signal. The curvature of the metal edge may vary from a completely flat edge, as shown in fig. 7, to an arbitrary curvature, as shown in fig. 5, for example. As for the inclination angle, the inclination angle may be changed as shown in fig. 9. Experimental results have shown that this tilt angle is optimized (i.e. a peak antenna gain is obtained) when the line of sight of the antenna is aligned with the direction of the signal beam. These results also show that the orientation of the metal edge is optimized when the lateral faces of the signal beam are aligned with the metal edge.

An omnidirectional dome antenna. The omni-directional dome antenna provides an effective way to omni-directionally cover a street or open place. Such antennas are located within a ground vault (where the top of the vault is at ground level, or slightly above or below ground level, and the antenna is below ground level), and include one or more omnidirectional antennas mounted within a cradle that is tilted upward toward the vault rim. Referring to fig. 10, vault 14 is typically at least partially (often completely) buried underground — in streets, sidewalks, or soil. The dome 14 is typically made of concrete or high strength plastic. Referring to fig. 11, the dome 14 of fig. 10 is shown with the cover or lid 22 removed. For the sake of clarity, the circuitry normally included in such vaults is not shown in the figures. A dome antenna structure is shown comprising an omnidirectional antenna 12 in the central portion of the dome 14, with supporting metal brackets 24 angled upward from the antenna elements to direct the antenna signal upward and toward the rim 26 of the dome 14. An edge effect is achieved when the RF signal passes through the top edge 26 of the metal bracket 24.

Referring to fig. 12, omni-directional dome antenna 12 is shown in greater detail. Fig. 12 shows a single omnidirectional antenna 12 in the central region, although for MIMO systems, multiple omnidirectional antenna elements are typically used in this region. Around the omnidirectional antenna 12 are drain holes 28, these drain holes 28 ensuring that rain does not pool around the antenna 12 when the dome 14 is submerged in rainy seasons. The antenna deflector plate 30 is angled upwardly toward the edge 26 of the dome 22 (not shown in fig. 12). In the preferred embodiment, the deflector plate 30 is made of aluminum sheet metal, approximately 1.5mm to 4.0mm thick, and may be made of any other metal or other radio-reflective material, such as steel, metal plastic, or a wire mesh product having a small mesh size compared to the wavelength of the radio frequency signal being transmitted. While the bracket 24, the rim 26, and the deflector plate 30 are shown as comprising a unitary piece of metal, embodiments are contemplated wherein the pieces of metal are separate and assembled in the field or at a manufacturing or assembly facility.

As shown in fig. 12, the omnidirectional antenna 12 has an integral plastic radome 32, because the dome may occasionally be flooded, the plastic radome 32 serving to protect the antenna element 12 from rain ingress when the dome is flooded. Alternatively, the bell jar may be used for deflector plates or dome caps through attachment points. The antenna deflector and bracket combination is generally angled upwardly and away from the antenna 12 with a substantially continuous edge 26 just below the dome cover. The upward slope, in combination with the substantially continuous edge of the antenna on or near the ground, diffracts the radio waves, bending them towards the ground, resulting in a higher effective antenna gain along the ground.

A directional dome antenna. Directional dome antennas provide an effective way to provide directional coverage of streets or open venues. The antenna is located within a vault generally above ground and includes one or more directional antennas mounted within a cradle that slopes upwardly toward the perimeter of the vault. Referring to fig. 13, the dome 14 is shown with a plastic reinforcing cover 22 and a plastic base 34. Referring to fig. 14, the dome 14 of fig. 13 is shown with the cover or lid 22 removed. The dome antenna structure includes a directional antenna 36 centrally located within the dome, supported by a deflector mount 38, the deflector mount 38 being angled upwardly from the antenna elements to direct the antenna signals upwardly and toward the rim or flange 40 of the dome 14. An edge effect is created along the top edge 26 of the metal bracket 38.

Referring to fig. 15-22, perspective and cross-sectional views of several commercial antennas 12 are shown. There are many vault manufacturers, each offering a variety of alternative vaults and sizes. The vault is generally longer than it is wide and is usually at least partially buried in the ground so that the longer portion is aligned with the direction of the street. According to a preferred embodiment, two types of directional dome antennas, mounted longitudinally and transversely, provide flexibility to the target area of the directional dome antenna.

The directional dome antenna preferably comprises a single directional antenna 36 in the central region 42, although for MIMO systems, multiple directional antenna elements are typically used. At the bottom of the directional antenna are drain holes (not shown in fig. 13-22) that ensure that rain does not pool around the antenna 36 when the vault is flooded in rainy seasons. The antenna deflector plate 44 is tilted upward and forward toward the desired dome top rim 26. The deflector plate 44 is made of a radioactive reflective material similar to the omni-directional deflector support 24 described above. As with the omnidirectional dome antenna embodiment, a bell jar may be used for the deflector plate or dome cover through the attachment point to ensure that rain does not affect the antenna 36 or associated RF cables (not shown).

The directional antenna deflector mount 48 is generally angled upward and away from the antenna 36 with the substantially continuous rim 26 just below the dome. The upward slope, in combination with the substantially continuous edge of the antenna on or near the ground, diffracts the radio waves, bending them toward the ground, resulting in a higher effective antenna gain along the ground. One or more tilt structures 50 may be provided to tilt the antenna 36 (in azimuth and/or elevation) to beamsteer the RF signals as desired. Likewise, an adjustment mechanism 52 may be provided to change the angle, elevation, grade, and/or position of the deflector plate 44 in order to adjust or control the main beam of the antenna 36.

In an alternative embodiment of the present invention, an active high power vault antenna may be provided that does not include a metal edge diffractor. For example, Wi-Fi using a dome antenna can be applied^TMA transceiver provided that sufficient gain can be obtained with a dome antenna that does not include a metal edge diffractor. If the antenna in fig. 1 is replaced by an active high power antenna, the gain at all required elevation angles is sufficient.

In another alternative embodiment of the invention, an RF transceiver using an antenna according to the above description may be applied. Such a transceiver may be implemented in the form of a multiband transceiver, or in the form of a multicarrier transceiver system, or in the form of a multiband, multicarrier transceiver system.

While the foregoing detailed description has set forth specific preferred embodiments of the present invention, it will be understood that the foregoing description is illustrative of the invention and is not to be construed as limiting thereof. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention.

Claims (23)

1. An edge effect vault directional antenna comprising:

a communications vault having a non-conductive cover disposed at ground level;

an antenna element connected to a mounting bracket and located in the communications vault; and

a rectangular metal reflector connected to the mounting bracket disposed adjacent to the antenna element, the rectangular metal reflector having four vertically inclined surfaces connected at their upper ends to horizontal straight edges disposed parallel to the ground, the metal reflector and the edges configured to produce an edge effect on an RF signal of the antenna to bend the RF signal in a direction toward the ground.

2. The fringe-effect vault directional antenna of claim 1, wherein the antenna element is disposed below ground.

3. The fringe-effect vault directional antenna of claim 1, wherein the non-conductive vault cover is disposed below ground.

4. The fringe-effect vault directional antenna of claim 1, wherein the non-conductive vault cover is disposed on a ground surface.

5. The fringe-effect vault directional antenna of claim 1, wherein the non-conductive vault cover is disposed above ground.

6. The fringe-effect vault directional antenna of claim 1, wherein the non-conductive vault cover comprises a material selected from the group consisting of concrete, concrete polymer, and plastic.

7. The fringe-effect vault directional antenna of claim 1, wherein the antenna element is connected with the vault cover.

8. The fringe-effect vault directional antenna of claim 1, wherein the antenna element is supported by the metal reflector.

9. The fringe-effect vault directional antenna of claim 1, wherein the metal reflector includes a tilted bracket configured to direct the RF signal toward the antenna element.

10. The fringe-effect vault directional antenna of claim 1, further comprising an elevation tilt structure configured to tilt an elevation of the antenna so that a main beam of RF signals is disposed toward the fringe.

11. The fringe-effect vault directional antenna of claim 1, further comprising an azimuth tilt structure configured to tilt an azimuth of the antenna.

12. The fringe-effect vault directional antenna of claim 1, further comprising an adjustment structure configured to adjust the reflector so as to control a main beam of the antenna element.

13. The fringe-effect vault directional antenna of claim 1, further comprising a mounting bracket configured to enable the antenna element to: (i) longitudinally within the dome, or (ii) transversely within the dome.

14. The fringe-effect vault directional antenna of claim 1, further comprising a bell jar connected to the vault cover, the bell jar configured to hold an air pocket around the antenna element.

15. The fringe-effect vault directional antenna of claim 1, wherein the vertical sloping surface is integral with the horizontal straight edge.

16. An edge effect vault antenna system comprising:

an antenna element connected to the mounting bracket;

an arched top cover;

a metal deflection plate connected to the mounting bracket, the metal deflection plate having four vertical inclined surfaces and a straight edge connected to a top of each vertical inclined portion to provide an edge effect to a signal of the antenna; and

a radio frequency cable having a plurality of radio frequency terminals,

the antenna elements, the deflector plate, and the radio frequency cable are integrated together in the dome, the radio frequency cable being configured to connect energy of a received radio frequency signal into at least one of the antenna elements.

17. A system for providing WLAN or cellular radio coverage, the system comprising:

at least one wireless transceiver;

a wired connection device; and

the fringe-effect vault antenna system of claim 16.

18. The system of claim 17, wherein the wired connection device is selected from the group consisting of DOCSIS, DSL, ADSL, HDSL, VDSL, T1, and E1.

19. The system of claim 17, wherein the antenna elements are configured to allow wideband, multi-carrier operation.

20. The system of claim 17, wherein at least one of the wireless transceivers comprises a plurality of wireless transceivers, the system further comprising a plurality of antenna elements, each of the plurality of antenna elements corresponding to a different one of the plurality of wireless transceivers.

21. An edge effect RF omni directional antenna structure, comprising:

an antenna element connected to a mounting bracket;

a rectangular deflector connected to the mounting bracket and having four vertically inclined portions, each vertically inclined portion configured to intersect a main beam of the antenna element; and

a straight edge connected to a top of each of the vertically inclined portions and configured to generate an edge effect on an RF signal of the antenna element to bend the RF signal in a downward direction from the straight edge.

22. The structure of claim 21, wherein the mounting bracket, the deflector, and the rim are integral.

23. A method of propagating RF signals for a communications vault having an antenna element below ground, comprising:

providing a rectangular vertical tilt deflector having four sections to intersect a main beam of the antenna element, wherein the deflector and antenna are connected to a mounting bracket; and

a straight edge is provided which is connected to the top of each of the vertically inclined portions to produce an edge effect on the RF signal of the antenna element, bending the RF signal in the direction of the ground.