Nope, the new fiber will be high dispersion compared to the old fiber and also will not have dispersion compensation along its length. The old cable was designed for OOK signaling. Previously optical signaling was 1 bit per symbol OOK (on-off-keying) and direct detection meaning you did not have any optical phase information to make dispersion corrections so the dispersion compensation was done in a specially designed fiber with the opposite sign slope for dispersion (DCF).

This fiber was also relatively high loss and has a narrower core which leads to higher nonlinearities in the link. The old cable tries to keep the dispersion within the range that OOK technologies can operate error-free (post FEC) so there's a lot of it typical at each repeater (EDFA). The newer coherent optical technology can transmit multiple bits per symbol (BPSK, QPSK) by encoding the bits in the optical phase. Since the phase is recovered at the receiver the dispersion accumulated in the fiber can be undone in DSP with a long enough FIR filter. So the need for dispersion compensation is gone with coherent optical. Taking out the DCF also reduces loss along the link reducing EDFA (amplifier) count and increasing spacing. Also nonlinear penalties on the newer higher dispersion fiber are lower which improves something called cycle slips that can punch through the FEC and cause you to take post-FEC errors.

The net result is that you should be able to transmit QPSK at 32GBd in 2 polarizations in maybe 80 waves in each direction.

2bits x 2 polarizations x 32G ~128Gb/s per wave or nearly 11Tb/s for 1 fiber. If this cable has 6 strands, then it could easily meet the target transmission capacity.

That jumped out at me too. My wild guess is that the older fiber is a 10G system, the new one is 40G.

From [1] > Unity cable system consists of eight fiber pairs, has design capacity up to 7.68 Tbps, with each fiber pair operating at 96x10G DWDM system.

From [2] > the SJC cable system consists of 6 fiber pairs with the initial design capacity of 28 terabits per second,

Taking a guess that there are 96x40Gb/s x 6 fibers gets you to 23 Tb/s, so in the right ballpark. (Wavelength spacing on a fiber is different between 40G and 10G, so this is a bit of a shot in the dark.)

Caveat: 40G used to be near and dear to my heart (Big Bear Networks), so everything pretty much looks like that nail to my hammer.

[1] http://submarinenetworks.com/systems/trans-pacific/unity [2] http://www.globe.com.ph/press-room/globe-regional-connectivi...

Your capitalization is incorrect. You wrote TB (terrabyte) when you meant Tb (terrabit). This equates to a 8x difference.