1. An optical fiber cable comprising:
a first aggregate layer including a plurality of first optical fiber units that are helically twisted together in a first direction without strand-back,
wherein each of the plurality of first optical fiber units has a plurality of optical fibers twisted together in a second direction, and
wherein the first direction and the second direction are different from each other.
2. The optical fiber cable according to claim 1, further comprising:
a second aggregate layer that surrounds the first aggregate layer,
wherein the second aggregate layer includes a plurality of second optical fiber units which are helically twisted together in the first direction without strand-back, and
wherein each of the plurality of second optical fiber units has a plurality of optical fibers twisted together in the second direction.
3. The optical fiber cable according to claim 1 or 2, further comprising:
a second aggregate layer that surrounds the first aggregate layer,
wherein the second aggregate layer includes a plurality of second optical fiber units which are helically twisted together in the first direction without strand-back, and
wherein twist pitch of the plurality of first optical fiber units and twist pitch of the plurality of second optical fiber units are equal to each other.
4. The optical fiber cable according to any one of claims 1 to 3, further

comprising:
a plurality of aggregate layers each including a plurality of optical fiber units, wherein when in a transverse cross-sectional view, a sum of cross-sectional areas of the plurality of optical fiber units included in the outermost aggregate layer located on the radially outermost side of the plurality of aggregate layers is defined as Ao, and a sum of cross-sectional areas of the plurality of optical fiber units included in the aggregate layers other than the outermost aggregate layer is Ai, a value of Ao H- Ai is 1.0 or more and 1.4 or less.