Abstract: An apparatus for map zooming includes instructions stored in a memory that when executed by a processor render a zoom bar. The zoom bar includes a plurality of map scale hash marks arranged along an axis of the zoom bar and indicative of a map scale range of a geographic map. The plurality of map scale hash marks include a first map scale hash mark representative of a first map scale, a second map scale hash mark offset along the zoom bar axis from the first map scale hash mark and representative of a second map scale, and a map transformation hash mark located between the first and second map scale hash marks and representative of a transformation of the geographic map from a first map data set defined with reference to the first map scale to a second map data set defined with reference to the second map scale.

Abstract: In one aspect, a sub-packet error correction method includes receiving a data packet, segregating the data packet into sub-packets, and encoding the sub-packets using an erasure code for transmission over a network, and receiving the encoded sub-packets, decoding the sub-packets, and combining the decoded sub-packets to reconstruct the data packet. In some embodiments, the data packet is received at a first proxy server for transmission over a lossy network, the encoded sub-packets received at a second proxy server over the lossy network.

Abstract: An apparatus for map zooming includes instructions stored in a memory that when executed by a processor render a zoom bar. The zoom bar includes a plurality of map scale hash marks arranged along an axis of the zoom bar and indicative of a map scale range of a geographic map. The plurality of map scale hash marks include a first map scale hash mark representative of a first map scale, a second map scale hash mark offset along the zoom bar axis from the first map scale hash mark and representative of a second map scale, and a map transformation hash mark located between the first and second map scale hash marks and representative of a transformation of the geographic map from a first map data set defined with reference to the first map scale to a second map data set defined with reference to the second map scale.