Headline specifications have been the focus of technology marketers since the inception of the spec sheet. Inevitably they steal the show – but who amongst us actually believes the miles per gallon claims put forward by car manufactures as accurate to their daily commute?
Data rate is the favored spec of the wireless broadband industry. Focusing narrowly on the stated figure can lead the reader astray on the practicality of the specification. More frequently, the headline specifications overshadow the key attributes that are relevant to the use case.
Released today, the PTP 650 has a headline data rate of 450 Mbps – a 50% increase over the highly regarded PTP 600. How is that for an attention grabber? While impressive, what might be more relevant to the network operator is its spectral efficiency of 10 bps/Hz, and its ability to operate in channel widths of 5, 10, 15, 20, 30, 40 and 45 MHz. While network operators will not achieve the headline data rate in a 5 MHz channel, they will be able to achieve the highest throughput possible from a sub-6 GHz TDD radio in that 5 MHz channel. Plus, they are far more likely to utilize a 5, 10 or 30 MHz channel; rather than the 45 MHz channel required to achieve the headline data rate.
Virtually every fixed wireless broadband radio today supports adaptive coding and modulation, and you will find that highlighted on the requisite specification sheet. These carrots at the end of the stick overshadow or even eclipse other capabilities: how many modulation rates (13 in the case of the PTP 650), sub carriers (1024 for the PTP 650); whether packets are lost on modulation rate shifts (not on the PTP 650); or most critically, how quickly the radio detects fade and shifts modulation rates (the PTP 650 leads the industry on this account).
Sometimes a specification that barely registers today becomes a must have feature in the future. IPv6 is an excellent example – how long ago did the experts predict we would run out of IPv4 addresses? As the true pivot point to IPv6 networks nears, a platform that supports both IPv4 and IPv6 individually or in a dual stack configuration sure sounds like an investment with a guaranteed return.
So don’t get hung up on the inevitable headline specifications. Understand what your operational requirements are today and likely to be in the future; study the specification and standards your industry is advancing; and build a specification sheet that meets your needs: If you are a utility, I suspect MPLS is in place or certainly on the horizon – are you specifying the ability to support 9600 byte packets on your backhaul platforms? If you are in the petrochem industry, the ability to support spatial diversity to overcome ducting or over-water shots might be paramount. Concerned about security? Then SNMPv3 and syslog might be high on your list. If you are a service provider in the midst of deploying your 4G network, then IEEE 1588v2 and SyncE are likely a deciding factors. A wireless Internet service provider is always trying to extend the edge of its network – what is the performance over range and link budget? 141db link budget at 64 QAM might just be your check box.
Have your own spec sheet ready? Look forward to seeing how PTP 650 matches up to it.