"simultaneously at the same time" is grammatically correct and usable in written English.
You can use this phrase when you want to emphasize that two events are happening at the same moment. For example: The audience member was simultaneously at the same time applauding and crying tears of joy.
"If civil discovery were to proceed simultaneously at the same time, therefore, it would unduly interfere with the integrity of the criminal proceedings.
To avoid the mutual interference, the SUs cannot report from the common channel simultaneously at the same time.
The two different types of headache may occur either at two different periods or simultaneously at the same time.
No oil tank is allowed to do delivery, export, switch, blending and fractionation operations simultaneously at the same time.
The two different types of headache may occur either at two different time periods or simultaneously at the same time [1 5].
In conventional half-duplex relay systems, where the relay node cannot transmit and receive simultaneously at the same time and frequency, four time-frequency slots are required for a two-way information exchange [10].
Mr. Ayckbourn wrote the plays concurrently in celebration of his 60th birthday, and they are being performed simultaneously -- at the same time by the same performers, who run between two different stages -- in what turns into an invigorating celebration of the possibilities of theater.
The user arrival process of this model captures the fact that the users in the network are not simultaneously active at the same time, but they rather become active when they start a data session that requires the download/upload of data [18 21].
Moreover, with the emergence of genomic techniques thousands of mRNAs can be simultaneously evaluated at the same time by DNA chip techniques [2] or by other more quantitative methods [3], [4].
For comparison, serum creatinine was simultaneously tested at the same time points.
Values of MAP, cardiac index, CVP, and rSO2 were continuously measured and simultaneously recorded at the same time points (every 5 min) until the completion of surgery.
