V. RELATED WORK
The in-network approach towards multihoming described in this paper is complementary to a rich literature supporting multihomed devices in the Internet.
Past proposals in this regard can be categorized based on the protocol layer at which
the support for multihoming resides.
Reference [13] proposes a network layer proxy mechanism for multihoming, but requires
fine-grained feedback of link quality information.
Schemes proposed in [14], [15] enable vertical handoffs between 3GPP,WiMax, however, they do not support striping of data over multiple cellular interfaces.
Moving upwards in the protocol stack, most recent efforts have gone towards a transport layer approach to multihoming support [16]–[18].
While these endto-end transport-layer proposals have started seeing some early deployments, they offer limited flexibility in the manner in which the multiple interfaces can be used.
Asymmetric paths provide further challenges to end-to-end TCP based multihoming implementations as shown in [19].
In this regard, Multipath TCP [20] allows multipath aware applications to express policy preferences and aggregate bandwidths over multiple redundant paths.
Authors in [21] perform extensive measurement based studies on MPTCP for dualhomed devices (with Wi-Fi and 3G/LTE).
The performance gains and the tradeoffs of flow size reported are similar to the
results presented in this work.
However, the key distinction that we would like to make is not performance based but implementation based.
MobilityFirst provides a cleaner network layer solution, with hop by hop reliable data delivery.
Firstly,the network has improved visibility compared to end-hosts which allows it to make better decisions.
Secondly, pushing the intelligence down to the routers allows the end-hosts to run a
variety of applications on top.
Intelligent devices could express their policy to use multiple redundant paths, similar to MPTCP,whereas legacy devices could let the network decide on their behalf and yet achieve comparable performance benefits.