Automotive Requirement: Harsh Environment
For automotive, the number of in-line connections is larger than supported by 10 GBASE-SR. In addition, the insertion loss of in-line connections is going to be larger due to dust, aging, and cost restrictions.
Currently available in-line connectors increase their insertion loss when vibrations are present. Thus, the number of allowable connectors will be reduced for a 10GBASE-SR link.
Present fiber and connectors age quickly when operated in a harsh automotive environment. This translates into a link power budget degradation (shorter lengths and/or fewer in-liners).
Modern connectors are not designed to withstand automotive dust specifications. As a result, they will get soiled and insertion losses will be increased (smaller number of in-liners and/or shorter link length allowed).
Dynamic Temperature Changes
Automotive applications require the communications system to adapt to quick temperature changes without any impact on the error rate or link performance. This means that the system needs to adapt its operation depending on the operating temperature. This is not possible with 10GBASE-SR: the system remains the same when temperatures change, and the impact on the performance translates into different parameter degradations such as link length, error rate, etc.
Further Automotive Requirements
There are also further automotive requirements that affect 10GBASE-SR and make it unsuitable for in-vehicle usage.
Automotive environments involve a high number of in-line connectors (up to 4) in a single link. This is not the case for applications that 10GBASE-SR was designed for. Automotive routing practices are aggressive with tight bends, which 10GBASE-SR also does not support.