  We present millimeter and radio observations of 13 SDSS quasars at reshifts
z~6. We observed eleven of them with the Max-Planck Millimeter Bolometer Array
(MAMBO-2) at the IRAM 30m-telescope at 250 GHz and all of them with the Very
Large Array (VLA) at 1.4 GHz. Four sources are detected by MAMBO-2 and six are
detected by the VLA at >=3 sigma level. These sources, together with another 6
published in previous papers,yield a submillimeter/millimeter and radio
observed SDSS quasar sample at z~6. We use this sample to investigate the
far-infrared (FIR) andradio properties of optically bright quasars in the early
universe. We compare this sample to lower redshift samples of quasars observed
inthe submillimeter and millimeter wavelengths ((sub)mm), and find that the
distribution of the FIR to B band optical luminosity ratio (L_FIR/L_B) is
similar from z~2 to 6. We find a weak correlation between the FIR luminosity
(L_FIR) and B band optical luminosity (L_B) byincluding the (sub)mm observed
samples at all redshifts. Some strong (sub)mm detections in the z~6 sample have
radio-to-FIR ratios within the range defined by star forming galaxies, which
suggests possible co-eval star forming activity with the powerful AGN in these
sources. We calculate the rest frame radio to optical ratios (R*_1.4=L_{v,
1.4GHz}/L_{v, 4400A}) for all of the VLA observed sources in the z~6 quasar
sample. Only one radio detection in this sample, J083643.85+005453.3, has
R*_1.4~40 and can be considered radio loud. There are no strong radio sources
(R*_1.4>=100) among these SDSS quasars at z~6. These data are consistent with,
although do not set strong constraints on, a decreasing radio-loud quasar
fraction with increasing redshift.
