Abstract:
Methods and apparatus are provided to facilitate the alignment of an antenna. In one aspect, there is provided a transceiver. The transceiver may include an antenna and a downconverter module coupled to the antenna. The downconverter module may convert a signal received at the antenna to another signal. The downconverter module may measure received signal strength. The transceiver may also include a sequence detector for detecting an error rate of a sequence included in the other signal. The transceiver may also include an output module for providing an output representative the error rate, the received signal strength, and a combination of the error rate and the received signal strength. The provided output may be used to enable alignment of an antenna. Related apparatus, systems, methods, and articles are also described.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of the following provisional application, all of which is incorporated herein by reference in its entirety: U.S. Ser. No. 60/988,697, entitled “E-Band Receiver And Bit Error Rate Measurement”, filed on Nov. 16, 2007 (Attorney Docket No. 37176-502PRO). 
     
    
     FIELD 
       [0002]    The present disclosure generally relates to receivers and, more particularly, E-band receivers. 
       BACKGROUND 
       [0003]    “E-Band” refers to any frequency within the following ranges: 71 to 76 gigahertz (GHz), 81 to 86 GHz, and 92 to 95 GHz. Transmissions in this frequency range are characterized by relatively short distances, such as distances on the order of about 10 miles and antennas with relatively narrow beamwidths, when compared to lower frequency transmission. For example, E-band communications may be used to solve the so-called “last mile” access challenge in situations where fiber optic connectivity is either too expensive or not a viable option. 
         [0004]    Recognizing the utility of E-Band communications, the Federal Communication Commission authorized rules for 13 GHz of spectrum in the E-Band frequency range (i.e., 71-76 GHz, 81-86 GHz, and 92-95 GHz) enabling multi-gigabit-per-second communications. This large amount of newly issued spectrum allows radio manufacturers to design low cost, multi-gigabit capacity wireless systems. Consequently, E-Band communication systems are being implemented using technologies, such as MMIC (monolithic millimeter wave integrated circuit) based wireless technology, to provide low cost and high performance communication systems. 
         [0005]    An obstacle to using E-Band communications is the alignment of antennas used in the E-Band frequency range. Since the frequencies are relatively high, the beamwidth of the antennas used in E-Band communications have very narrow beamwidths, when compared to traditional microwave antennas. The narrow beamwidths of E-Band antennas make it more difficult to align the antenna. For example, when establishing an E-Band communication link using two E-Band transceivers, the antennas must be aligned to enable communications. Poor alignment may result in no signal or a degraded signal at the E-Band transceiver. 
       SUMMARY 
       [0006]    The subject matter disclosed herein provides methods and apparatus for providing a receiver including at least one of a bit Error Rate (BER) measurement and a received signal strength measurement. 
         [0007]    In one aspect, there is provided a receiver. The receiver may include an antenna and a downconverter module coupled to the antenna. The downconverter module may convert a signal received at the antenna to another signal. The downconverter module may measure received signal strength. The receiver may also include a sequence detector for detecting an error rate of a sequence included in the other signal. The receiver may also include an output module for providing an output representative of the error rate, the received signal strength, and a combination of the error rate and the received signal strength. The provided output may be used to align an antenna. 
         [0008]    The subject matter described herein may be implemented to realize the advantage of enabling enhanced alignment of antennas by providing an indication representative of the quality of the alignment. 
         [0009]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive. Further features and/or variations may be provided in addition to those set forth herein. For example, the implementations described herein may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed below in the detailed description. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0010]    In the drawings, 
           [0011]      FIG. 1  depicts a block diagram of a system  100  including a transceiver  150  including a mechanism for measuring error rate (e.g., using a PRBS (pseudorandom bit sequence) generator  116 ) and for measuring signal strength (e.g., received signal strength indication (RSSI)); 
           [0012]      FIG. 2  depicts a block diagram of a system  200  including transceivers  250   a - b , both of which include mechanisms for measuring error rate and for measuring signal strength; 
           [0013]      FIG. 3  depicts a process  300  for aligning an antenna using error rate and signal strength; and 
           [0014]      FIG. 4  depicts a user interface for presenting measured error rate and signal strength. 
       
    
    
       [0015]    Like labels are used to refer to same or similar items in the drawings. 
       DETAILED DESCRIPTION 
       [0016]    As frequencies increase, it becomes increasingly difficult to align antennas. For example, the acceptance angle of a directional receive antenna of a given size becomes narrower, making it difficult to properly align an antenna. More problematic, when millimeter wave (MMW), including E-Band, communication links are used, the beamwidth of the receive antennas are extremely narrow, making a difficult alignment task even more difficult. 
         [0017]    Multi-path and reflections may also contribute to the difficulty in aligning antennas. Specifically, during a conventional antenna alignment, the antenna may be adjusted based on the strength of the signal received by the antenna (e.g., a received signal strength indication (RSSI)). For example, with a conventional approach, the antenna of a receiver is aligned (e.g., adjusted in azimuth and elevation) until the received signal strength measurement, as measured by RSSI, is optimum (e.g., at a maximum or near maximum)—indicating antenna alignment between the transmit antenna and the receive antenna. These conventional approaches may lead to improper alignment because multi-path and reflections may add to the signal strength—increasing RSSI at the receiver. However, the increased RSSI may not represent an optimum alignment since any increases in RSSI may be due to multi-path and reflections contributing to the received signal, resulting thus in higher received signal strength but an increase in bit errors of the underlying data in the received signal. As such, although signal strength (e.g., RSSI) may be optimum, the antenna alignment may not be optimum due to bit errors. 
         [0018]    The subject matter described herein incorporates a bit error measurement (e.g., BER) mechanism, a signal strength measurement mechanism (e.g., RSSI), or a combination of both into a receiver, such as an E-Band receiver. By providing a receiver including bit error measurement mechanisms and/or signal strength measurement mechanisms, a technician may monitor the error rate (e.g., BER, severely-errored seconds, and the like) in real-time while aligning the pointing angle of an antenna. Moreover, the alignment may be further enhanced by using RSSI measurements of the received signal. In some implementations, the time required to align an antenna is reduced, and the quality of the alignment is enhanced. Moreover, including bit error measurement mechanisms (e.g., a PRBS (Pseudorandom Bit Sequence) generator capable of measuring bit errors) may eliminate the need for a separate, external BER tester. Since many antenna alignments are performed on a tower, providing a receiver including a bit error measurement and/or a signal strength measurement may make the alignment process easier in these high-altitude environments. 
         [0019]      FIG. 1  depicts a transceiver  150  including a tributary interface  112 , a PRBS generator  116 , an RF up/downconverter transceiver  126 , a user interface processor  114 , a combiner  130 , a combined output module  140 , and a computer  105  including a user interface  107 . 
         [0020]    The transceiver  150  may be implemented to include at least one of a receiver and a transmitter. A transceiver refers to a radio that includes at least one of a transmitter and a receiver, and, in some cases, the transmitter and receiver are combined in a single, device. In some implementations, transceiver  150  may operate at one or more E-band frequencies. Although transceiver  150  may be implemented to transmit and receive RF signals  190  in the E-band frequency range, other frequencies may be used as well, such as MMW (e.g., 30 GHz to 300 GHz). 
         [0021]    Tributary interface  112  receives an input signal  110   a  and converts it from a user provided format, such as an optical signal, to an electrical signal. For example, input signal  110   a  may be an optical signal, such as Gigabit Ethernet or Fibre Channel signal, and may include data. Tributary interface  112  may also receive an electrical signal (e.g., a signal received at antenna  162  and processed by RF up/downconverter transceiver  126 ) and convert that signal to an output signal  110   b , such as Gigabit Ethernet or Fibre Channel signal. In some implementations, tributary interface  112  may be omitted or, alternatively, may be implemented as another type of interface. 
         [0022]    PRBS generator  116  may be implemented to perform at least one of sequence detection and sequence generation. For example, PBRS generator  116  may generate a sequence of data (e.g., bits). Moreover, this data sequence may have properties, such as pseudo randomness. For example, a PRBS may be generated by PRBS generator  116  and transmitted by transceiver  150 . Since the PRBS is a known (or a determinable) sequence, a receiver of the PRBS is able to determine how many bits in that PRBS had errors due to the transmission from transceiver  150  to the distant receiver (not shown). PRBS generator  116  may also receive one or more data sequences, such as a PRBS, and detect the number of bits of the data sequence that are in error. For example, PRBS generator  116  may generate and/or detect one or more of the following data sequences: an unframed PRBS of length 2 7 -1; an unframed PRBS of length 2 23 -1; an unframed PRBS of length 2 31 -1; predefined patterns of data; and special purpose data sequences, such as the Fibre Channel CRPAT, CJTPAT, and CSPAT patterns. Moreover, PRBS generator  116  may perform one or more of the following: provide clock and data recovery for Gigabit Ethernet and Fibre Channel; provide retiming of a signal; provide a repeater function; provide signal equalization; provide signal de-emphasis; and provide a driver (i.e., amplification) of a signal. 
         [0023]    In some implementations, a Vitesse Semiconductor VSC8228 chip is used to generate and detect the PRBS, although other devices may be used as well. When a Vitesse Semiconductor VSC8228 chip is used as PRBS generator  116 , the VSC8228 chip may be installed on a circuit board and may be coupled to a separate PIC controller to interface to user interface processor  114 . Commands from user interface processor  114  (e.g., input or provided by a user of user interface  107 ) control the BER function of the VSC8228. The user interface processor  114  may also be used to transform the BER information provided by PRBS generator to a frequency signal, which may be provided to combiner  130 . The frequency signal may be combined (e.g., summed) with the RSSI signal (e.g., an analog voltage) to provide a single, combined output at combined output  140 . The combined output  140  may be provided at an output port (e.g., one or more connectors, one or more interfaces, and the like) to be used to view independently the BER, RSSI, or a combination of the two. 
         [0024]    RF up/downconverter transceiver  126  is coupled to antenna  162  and may include at least one of a transmit path and receive path. The receive path receives an RF signal  190  from antenna  162  and may include a downconverter, demodulation components, and the like to provide demodulated data to tributary interface  112  (e.g., user data sent as output signal  110   b ) or PRBS generator  116  (e.g., a PRBS). The transmit path may be used to transmit a signal, such as data, a baseband signal, and the like, and convert that signal to another signal, such as an RF signal  190  for transmission by antenna  162 . For example, the transmit path may include an upconverter, modulation components, amplifiers, and the like to modulate and upconvert data provided by the tributary interface  112  (or a PRBS provided by PRBS generator  116 ) and transmit an RF signal including the data (or the PRBS) via antenna  162 . RF up/downconverter transceiver  126  may also include a power measurement device that measures the received signal strength (e.g., in terms of signal-to-noise ratio, dB, dBm, and the like) and provides the measured RSSI to combiner  130 . In some implementations, RF up/downconverter transceiver  126  may receive an RF signal at a carrier frequency at an E-Band frequency. The received RF signal is downconverted from the carrier frequency to another signal, such as intermediate frequency signal. In some cases, the other signal at the intermediate frequency is downconverted to another, lower frequency to provide a baseband signal including data (or the PRBS) for use by PRBS generator  116 . The received signal power may be measured at any location, including at the carrier frequency, intermediate frequency, or at baseband. 
         [0025]    Antennas  162  may be implemented as one or more antennas. For example, antenna  162  may be implemented as any antenna suitable for use in the E-Band frequency range. Examples of such antennas include: a horn antenna, a dish antenna, and a multiple input multiple output antenna system. In some implementations, antenna  162  is coupled to transceiver  150  in a fixed manner. When this is the case, aligning antenna  162  requires aligning the antenna  162  and the coupled transceiver  150 . In other implementations, although antenna  162  is coupled to transceiver  150 , antenna  162  may be aligned separately from transceiver  150 . When this is the case, aligning antenna  162  includes only aligning antenna  162 . 
         [0026]    To transmit, RF up/downconverter transceiver  126  receives a signal (e.g., an input signal  110   a  or a PRBS generated by PRBS generator  116 ) and modulates that signal on to a carrier, which may be upconverted for transmission as another signal, such as RF signal  190 . 
         [0027]    To receive, RF up/downconverter transceiver  126  receives a signal from antenna  162 ), downconverts the signal (e.g., from an E-band frequency to an intermediate frequency) and then demodulates to provide another signal, such as a baseband signal (e.g., data and the like), so it can be processed by PRBS generator  116  (e.g., to detect any sequences, such as a PRBS) or provided to another device (e.g., to tributary interface  112  for conversion to output signal  110   b ). 
         [0028]    User interface processor  114  may be used to interface to PRBS generator  116 . Specifically, user interface processor  114  may enable selection of a type of PRBS for generation by PRBS generator  116 . The generated PRBS may be transmitted through antenna  162  and RF up/downconverter transceiver  126 . Moreover, user interface processor  114  may also receive information regarding a PRBS detected by PRBS generator  116  and provide the information to user interface  107  for presentation and/or provide the information to combiner  130  for combining with other information, such as RSSI information. For example, user interface  107  may be used to select a type of PRBS sequence (e.g., a length or a type of pattern). When selected, user interface  107  provides an indication of the selection to user interface processor  114 , where the selection is transformed into commands for PRBS generator  116 . In some implementations, user interface processor  114  may be coupled to, or include, a PIC (Peripheral Interface Controller) microcontroller to interface to PRBS generator  116 . 
         [0029]    When a PRBS is detected by PRBS generator  116 , an error rate may be determined for the detected PRBS. The determined error rate may be provided to user interface processor  114 , which provides the error rate to combiner  130 . For example, the BER determined by PRBS generator  116  may be provided to combiner  130  as an analog signal (e.g., a BER value having a corresponding analog frequency value, a voltage value, and the like). 
         [0030]    For a signal received at antenna  162 , combiner  130  may be used to combine the BER detected by PRBS generator  116  and the RSSI measured for the received signal. This combined output signal may be provided as combined output  140 . When a user is aligning antenna  162 , the combined output measurement may include error rate information (e.g., BER), signal strength information (e.g., RSSI), or a combination of the two. This combined measurement of BER and RSSI may enhance the alignment of antenna  162  in the presence of multi-path and reflections since an optimum received power measurement, such as RSSI, is not the only factor considered during antenna alignment, as BER is also a factor used to align the antenna. 
         [0031]    Although combiner  130  is depicted in  FIG. 1 , combiner  130  may be implemented as any mechanism for combining the BER and RSSI information. For example, combiner  130  may be implemented as one or more of the following: a summing amplifier, discrete logic, and digital implementations (e.g., converting the BER and RSSI information into a digital form and combining them digitally). 
         [0032]    Moreover, although combined output  140  is depicted in  FIG. 1 , transceiver  150  may provide individual outputs for the BER and RSSI as well. For example, a voltage and/or frequency output proportional to the BER may be provided as combined output  140  to enable use of a voltmeter or a frequency counter as the real-time indicator of the BER during antenna alignment. If a frequency signal is utilized, an audio loudspeaker or headphones may be used to permit alignment without the need to view a meter, which may be difficult to read in bright daylight. A user aligning the antenna may listen for a change in an audio tone or a frequency of ticks indicating a change in the BER. If a frequency signal is utilized for BER, audio intensity may be used to represent RSSI (e.g., the louder the intensity of the audio, the higher the relative RSSI). 
         [0033]    In some implementations, custom signals may be used to represent different values of BER, RSSI, and a combination of both. For example, if the BER exceeds a threshold minimum, a ring tone may be broadcast as an audio signal. In some implementations, user interface  107  also presents detailed output information representative of the BER and/or RSSI. For example, during testing, user interface  107  may present the real-time error rate and RSSI both numerically and graphically, e.g., with a bar graph, using colors, etc. 
         [0034]      FIG. 2  depicts two transceivers  250   a  and  b . The transceivers  250   a - b  are similar to transceiver  150  in many respects. However, transceivers  250   a - b  each include a switch, such as a multiplexer or switches  218   a - b , for selecting between a reference clock, such as reference clocks  220   a - b , and a clock recovery module, such as clock recovery modules  222   a - b.    
         [0035]    Switches  218   a - b  enable loop back testing (e.g., loop  210 ), as described further below. Moreover, transceivers  250   a - b  depict additional features, such as frequency counter  292   a - b , a voltmeter  294   a - b  to present RSSI information, and a loudspeaker  296   a - b  to provide an audio indication of the RSSI, BER, or a combination of the two. 
         [0036]    Switches  218   a - b  may be used to switch between reference clocks  220   a - b  and clock recovery modules  222   a - b . Reference clocks  220   a - b  provide reference clocks for communications between transceiver  250   a  and  250   b . When clock recovery  222   a - b  is used, the transceiver using clock recovery is able to recover a clock signal from a signal received from the antenna and RF up/downconverter transceiver. 
         [0037]    In some implementations, user interface  107  sends commands to the PRBS generator  116 . The commands select that a BER should be performed between the transceivers  250   a - b . In some cases, user interface  107  may command that a loop back test be performed using BER and RSSI to test the RF communication links between transceiver  250   a  and transceiver  250   b .  FIG. 2  depicts a loop  210  to enable testing of both transceiver  250   a  and transceiver  250   b . Although  FIG. 2  depicts loop  210  at tributary interface  212 , such a loop may be implemented at other locations in transceiver  250   b.    
         [0038]    Although  FIG. 2  depicts transceivers  250   a - b  implemented using similar components, in some implementations, transceivers  250   a - b  may be implemented differently. Moreover, during a test of transceivers  250   a - b , the transceivers  250   a - b  may be configured differently. The systems  100  and  200  depicted at  FIGS. 1 and 2  are block diagrams representations and may include additional components, connectors, and the like. Furthermore, one or more aspects of systems  100  and  200  may be implemented as hardware, software, and firmware. 
         [0039]    For example, transceiver  250   b  may provide a loop to return any received test sequences (e.g., a PRBS) to transceiver  250   a.    
         [0040]    In a so-called “full loop back,” PRBS generator  116  receives a command from user interface processor  114  to ignore (e.g., inhibit) any data from input signal  110   a  and tributary interface  112 . PRBS generator  116  also receives a command to generate a data sequence (e.g., a PRBS) based on reference clock  220   a  and provide the generated PRBS to RF up/downconverter transceiver  126 . RF up/downconverter transceiver  126  modulates and upconverts the generated bit sequence for transmission at antenna  162 . The transmitted signal may be transmitted as RF signal  190  in the E-band frequency range, although other frequencies may be used as well. 
         [0041]    Transceiver  250   b  receives the RF signal  190  at antenna  262 . Antenna  262  is coupled to RF up/downconverter transceiver module  216 , so that the received signal may be downconverted and demodulated. The demodulated signal includes the data sequence (e.g., a PRBS) transmitted by transceiver  250   a . In full loop back, PRBS generator  226  allows the PRBS transmitted by transceiver  250   a  to pass from up/downconverter transceiver  216  to tributary interface  212 , where a loop  210  is provided. The loop  210  enables the PRBS transmitted by transceiver  250   a  to be looped back through the transmit path of transceiver  250   b  (e.g., passing through PRBS generator  226  and modulated and upconverted for transmission by RF up/downconverter transceiver  216  and antenna  262 ). In some implementations, user interface  107  and/or user interface processor  114  remotely controls whether loop  210  should be applied. 
         [0042]    Transceiver  250   a  receives from transceiver  250   b  the looped back PRBS. The PRBS is received by PRBS generator  116  through antenna  162  and RF up/downconverter transceiver  126 . PRBS generator  116  detects the received PRBS. PRBS generator  116  then detects any bits in the sequence (e.g., the PRBS) that are in error. PRBS generator  116  provides to user interface processor  114  information regarding the quantity of bit errors (e.g., the bit error count and/or BER). In some implementations, user interface processor  114  may calculate a BER from the quantity of bit errors. Any detected bit errors or determined BER may be provided to user interface  107  for presentation numerically and graphically at computer  105  (e.g., at a computer, a laptop, a handheld computer, or the like). 
         [0043]    User interface processor  114  may also generate a frequency signal that is proportional to the error rate. The combiner  130  may combine the frequency signal representing BER with an analog voltage signal representing RSSI (e.g., an analog voltage proportional to measured received signal strength) of the signal received at antenna  162 . The combined frequency signal and analog voltage signal provide a single output (e.g., combined output  140 ) that may be simultaneously connected to a DC voltmeter and a frequency counter. In this manner, a technician may monitor RSSI, BER, or a combination of both, when aligning an antenna, such as antenna  162 , eliminating the need for a separate computer, such as computer  105 . 
         [0044]    A full loop back may also be performed from transceiver  250   b . When this is the case, user interface processor  214  controls PRBS generator  216  to generate a bit sequence (e.g., a PRBS) for transmission through RF up/downconverter transceiver  216  and antenna  262  and detect the PRBS received during the full loop back of transceiver  250   a . In this case, transceiver  250   a  would include a loop similar to the one described above with respect to loop  210 . Any detected bit errors or determined BER may be provided to user interface  207  for presentation numerically and graphically at computer  205  (e.g., at a computer, a laptop, a handheld computer, or the like). 
         [0045]    For example, transceiver  250   b  receives from transceiver  250   a  the looped back data sequence, e.g., the PRBS. The PRBS is received by PRBS generator  216  through antenna  262  and RF up/downconverter transceiver  226 . PRBS generator  226  detects the received data sequence (i.e., a PRBS) to detect any bit errors. PRBS generator  226  provides to user interface processor  214  information representative of the quantity of bit errors (e.g., the real-time bit error count and BER). Any detected bit errors or determined BER may be provided to user interface  207  for presentation numerically and graphically at computer  205  (e.g., a computer, a laptop, a handheld computer, or the like). 
         [0046]    User interface processor  214  may also generate a frequency signal that is proportional to the error rate. The combiner  230  may combine the frequency signal with an analog voltage representative of RSSI (e.g., an analog voltage proportional to measured received signal strength) of the signal received at antenna  262 . The combined signal provides a single output (e.g., combined output  240 ) that may be simultaneously connected to a DC voltmeter and a frequency counter. In this manner, a technician may monitor both RSSI and BER when aligning an antenna, such as antenna  262 . 
         [0047]    In some implementations a so-called “uni-directional” test is performed. In the uni-directional test mode, both transceivers  250   a - b  are each configured to generate and detect the data sequence (e.g., a PRBS). Unlike the full loop back described above, the uni-directional mode tests each link separately, i.e., the downlink from transceiver  250   a  to transceiver  250   b  and the uplink from transceiver  250   b  to transceiver  250   a.    
         [0048]    In a unidirectional test, switch  218   b  is configured to select clock recovery  222   b . In this manner, the entire system  200  uses one reference clock, thus the detectors in PRBS generators  116  and  226  may synchronize with the received data even when the pattern was not generated at the respective PRBS generators  116  and  226 . Valid BER can be measured and displayed for each direction independently. 
         [0049]    In a unidirectional test, PRBS generator  116  receives a command from user interface processor  114  to ignore any data from input signal  110   a  and tributary interface  112 . PRBS generator  116  also receives a command to generate a data sequence (e.g., a PRBS) based on reference clock  220   a  and provide the generated PRBS to RF up/downconverter transceiver  126 . RF up/downconverter transceiver  126  modulates and upconverts the generated bit sequence for transmission at antenna  162 . The transmitted signal may be transmitted as RF signal  190  in the E-band frequency range, although other frequencies may be used as well. 
         [0050]    Transceiver  250   b  receives the RF signal  190  at antenna  262 . Antenna  262  is coupled to RF up/downconverter transceiver module  216 , so that the received signal may be downconverted and demodulated. The demodulated signal includes the data sequence (e.g., a PRBS) transmitted by transceiver  250   a . In unidirectional mode, clock recovery  222   b  receives from RF up/downconverter transceiver  216  a signal, such as data sequence (e.g., the PRBS generated by transceiver  250   a ), from which clock recovery  222   b  can recover a clock signal. Switch  218   b  selects clock recovery  222   b , so that the recovered clock can be provided to PRBS generator  226 . The recovered clock is used by PBRS generator  226  to detect the bit errors of the PRBS of the received signal and to generate another PRBS for transmission through antenna  262  and RF up/downconverter transceiver module  216 . PRBS generator  216  may provide to user interface processor  214  information regarding the quantity of bit errors (e.g., the real-time bit error count and BER). In some implementations, user interface processor  214  may calculate a BER from the quantity of bit errors. Any detected bit errors or determined BER may be provided to user interface  207  for presentation numerically and graphically at computer  205  (e.g., at a computer, a laptop, a handheld computer, or the like). The detected errors or determined BER may also be transmitted to computer  105  and user interface  107  (e.g., through antennas  162  and  262  or through another network, such as the Internet). For example, the detected errors or determined BER may be transmitted to computer  105  and user interface  107  via an over-the-air management channel embedded in the data sent through antennas  162  and  262  or provided to a coupled network management host. 
         [0051]    At transceiver  250   a , the RF signal including the PRBS from transceiver  250   b  is received by PRBS generator  116  through antenna  162  and RF up/downconverter transceiver  126 . PRBS generator  116  detects the PRBS and any bits that are in error. PRBS generator  116  provides to user interface processor  114  information regarding the quantity of bit errors (e.g., the real-time bit error count and BER). In some implementations, user interface processor  114  may calculate a BER from the quantity of bit errors. Any detected bit errors or determined BER may be provided to user interface  107  for presentation. 
         [0052]      FIG. 3  depicts a process  300 . At  310 , a PRBS is received at a transceiver. At  320 , a BER is determined based on the received PRBS. For example, a PRBS generator at the transceiver may detect the received PRBS and determine a quantity of bits in error. At  330 , an indication of received signal strength (e.g., RSSI) may be determined (e.g., measured). For example, transceivers may include a power measurement mechanism at the antenna, the RF up/down conversion transceiver, and other locations as well. At  340 , an output representing a determined RSSI and/or determined BER may be provided. At  350 , the provided output may be used to align an antenna, such as an E-Band antenna coupled to the transceiver. 
         [0053]      FIG. 4  depicts an example of a user interface  107  presented at computer  105 . User interface  107  includes BER and RSSI information (e.g., BER=5.50E-07 and RSSI=2.48 V). User interface  207  may present information in a similar manner to  FIG. 4 .  FIG. 4  also depicts a so-called strip chart  410 . The strip chart  410  presents bit error rate measurements over time. For example, strip chart  410  presents bit error rate (e.g., E-11 to E-02) over time (e.g., 0 to 15 sec). Strip chart  410  depicts a 15 second interval of bit error rate measurements, although other intervals may be selected by providing another interval at  412 . 
         [0054]    The foregoing description is intended to illustrate but not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims.