Branching Unit Deployment On Ship

A branching unit moving on a conveyor belt to be lowered into the ocean. Branching units have evolved from simply splitting the fibre pairs into two paths to switching fibre pairs and wavelengths. This enables bandwidth to be allocated to the path where demand is the greatest.

Photo of a Subsea Cable Branching Unit on a Ship Conveyor Belt


Comments

Post a Comment

Popular posts from this blog

The British Empire's Resilient Subsea Telegraph Network

Image
The British empire had largely completed its Red Line cable network by 1902. This network allowed news and messages to be delivered in a few minutes or several hours at most depending on the message queue's length. It spanned the globe and formed a network ring so traffic could be routed in the opposite direction in case of disruption. It was, as Dr. Michael Delaunay has argued, a highly resilient network. Besides the ring configuration, the network relied on multiple cables between any pair of given end points to ensure uptime. The British military believed it would be impossible for an enemy to cut enough cables on any route to sever all communications between any given pair of end points. The Committee of Imperial Defense concluded that 57 cables must be shut down to isolate the British Isles from the Red Line network. The figure was 15 for Canada and 7 for South Africa. The Empire was self sufficient in terms of manufacturing the components for a subsea telegraph cable and re...
Read more

The Short Life Expectancy of Starlink's LEO Satellites

Image
According to FCC filings Starlink shut down almost 500 Starlink satellites during the first half of 2025. The company had them reenter the atmosphere where they burned up. What is striking is that these satellites were all less than 5 years old. The general consensus is that LEOs have a life expectancy ranging from 5 to 8 years. Shorter than expected life spans for the satellites will hit Starlink's income statement hard by increasing network depreciation and replacement needs. However, Starlink has managed to lower its LEO's manufacturing costs down to $500K versus initial figures around $1 million. So these production economies of scale might offset some of the higher than expected depreciation. However, there are also rocket launch costs as well. It costs Starlink about $3 million to put a satellite into orbit. The Falcon 9 costs $67 million per flight and delivers 23 LEOs into low Earth orbit. As a private company Starlink financials are a bit of mystery. The company press ...
Read more

Southern Cross Subsea Cable Network Deploys Ciena's Granular Layer 1 Wavelength Product

Image
Southern Cross subsea cable system is implementing ODUflex, which is a relatively new ITU standard that allows granular Layer 1 bandwidth. No longer are we limited to 100G, 400G, and 800G for either subsea or terrestrial networks. Interestingly enough, Hauwei proposed the new standard and was its primary champion. All wavelengths consist of optical containers and ODUflex allows optical containers to be stacked at 1.25 Gps intervals. So you can lease 1.25 Gbps wavelength up to 400G in 1.25 Gbps increments. Note that port sizes are still 10G, 100G, 400G or 800G. So to access a 150G transmission rate the customer needs 400G intefaces. Ciena is one of the the vendors to implement ODUflex along with Hauwei. More details here: https://lnkd.in/dZvNbubc. It is worth noting that granular bandwidth is being implemented on the newer cables which Southern Cross owns like Next.  The commercial motivation is poor take up of 400G wavelengths. The only real customers for 400Gs are very big bandwi...
Read more